0:00:33 > 0:00:36Once in a while you get an offer you can't refuse.
0:00:39 > 0:00:42It's every schoolboy's dream.
0:00:46 > 0:00:50Biggles was never like this.
0:00:53 > 0:00:58Nearly ready! No point going unless you're fully equipped...
0:00:58 > 0:01:01inflatable trousers...
0:01:01 > 0:01:05all purpose cutting tool... and most vital of all...
0:01:05 > 0:01:08sick bag.
0:01:08 > 0:01:11So long, Ground Force, hello...
0:01:11 > 0:01:15Air Force. Oooohhh!
0:01:18 > 0:01:24From up here you can appreciate how wonderful our landscape is.
0:01:24 > 0:01:29I'm also on a mission to explore the past.
0:01:29 > 0:01:32We're doing about 600 miles per hour.
0:01:32 > 0:01:37At that speed I can get from London to the tip of Scotland in about an hour.
0:01:41 > 0:01:45But in that same one-hour flight, I am also making another journey,
0:01:45 > 0:01:49one that crosses the entire history of our islands.
0:01:56 > 0:01:59Every landscape that's flashing by beneath me
0:01:59 > 0:02:03has been shaped over millions of years by momentous events!
0:02:05 > 0:02:10So if you want to know why Britain looks the way it does, then hang on.
0:02:10 > 0:02:13You're in for one heck of a ride!
0:02:19 > 0:02:23We've been blown apart by volcanic explosions.
0:02:25 > 0:02:30Our islands have been raised up into peaks as high as the Himalayas.
0:02:32 > 0:02:38We've been part of a desert bigger than the Sahara,
0:02:38 > 0:02:41and submerged beneath great oceans.
0:02:47 > 0:02:51We've been cloaked in rainforests,
0:02:51 > 0:02:56and even had our very own Jurassic Park!
0:03:01 > 0:03:06Our landscape is littered with clues that both reveal our past
0:03:06 > 0:03:10and explain our present.
0:03:10 > 0:03:15They'll guide me on this journey to uncover the origins of the British Isles.
0:03:22 > 0:03:25Those are the Outer Hebrides down there,
0:03:25 > 0:03:31and that's where our story begins.
0:03:31 > 0:03:36The Isle of Lewis is one of Britain's wildest, most remote places.
0:03:36 > 0:03:38This place feels ancient,
0:03:38 > 0:03:43and it's where the connection between landscape and the underlying rock is laid bare.
0:03:46 > 0:03:51These are the standing stones of Callanish.
0:03:51 > 0:03:55They were raised 5,000 years ago, making them old enough
0:03:55 > 0:03:59to pre-date the pyramids of Ancient Egypt!
0:04:03 > 0:04:10The earliest settlers here used the local rocks to build this spectacular monument.
0:04:10 > 0:04:15Part ceremonial, part calendar, these stones were used
0:04:15 > 0:04:18to chart the passage of the sun, moon and stars across the sky...
0:04:20 > 0:04:23a kind of ancient farmer's almanac.
0:04:28 > 0:04:34This ancient timepiece has been tracking the seasons for generations,
0:04:34 > 0:04:38but the rock it's made from records events from a more distant past.
0:04:38 > 0:04:415,000 years seems like a long time,
0:04:41 > 0:04:47but it's the blink of an eye compared with the age of the stones.
0:04:47 > 0:04:49They're the real reason I'm here.
0:04:49 > 0:04:53They've been on a remarkable journey through time.
0:04:57 > 0:05:05These rocks are nearly three billion years old, by far the oldest things in Britain.
0:05:09 > 0:05:14They were created at a time when the whole planet was in a state of flux.
0:05:14 > 0:05:18The map of the world would have been totally unrecognizable.
0:05:18 > 0:05:22Even half a billion years ago, the British Isles didn't exist.
0:05:27 > 0:05:35For a start, Scotland and Ireland were near the equator while England and Wales were near the South Pole!
0:05:35 > 0:05:40But powerful forces deep within the Earth were carrying these pieces
0:05:40 > 0:05:45steadily towards each other at just a few centimetres each year.
0:05:50 > 0:05:57Until finally, somewhere south of the equator, these pieces crashed together.
0:06:06 > 0:06:10HELICOPTER ENGINE WHIRS
0:06:11 > 0:06:14This is where they met!
0:06:14 > 0:06:16That's the Scottish chunk,
0:06:16 > 0:06:19and England down to the south.
0:06:19 > 0:06:23The join itself is buried hundreds of metres below the moorland peat,
0:06:23 > 0:06:30but it runs alongside a far more obvious and famous boundary between North and South -
0:06:30 > 0:06:32Hadrian's Wall.
0:06:32 > 0:06:36When Hadrian built the wall almost 2,000 years ago,
0:06:36 > 0:06:40he had no idea how important this place was in Britain's history.
0:06:40 > 0:06:42But if you know where to look,
0:06:42 > 0:06:46there are signs all over the British Isles of the monumental events
0:06:46 > 0:06:50that accompanied this first "act of union" between England and Scotland.
0:06:58 > 0:07:04And some of the most impressive are north of this border, among our highest peaks.
0:07:06 > 0:07:08The Scottish Highlands.
0:07:16 > 0:07:21This landscape is just about as untamed as Britain can get.
0:07:21 > 0:07:24Our last true wilderness.
0:07:59 > 0:08:03This is Aonach Mor, in the heart of the Highlands.
0:08:03 > 0:08:10It's a Munro - one of the 280 peaks in Scotland that rise above 3,000 feet.
0:08:10 > 0:08:16They're named after an Edwardian mountaineer, Hugh Munro, who was the first to record them...
0:08:16 > 0:08:18and climb them.
0:08:18 > 0:08:20He must have been a tough guy.
0:08:20 > 0:08:23But the mountains beat even him.
0:08:23 > 0:08:28Sadly, Munro died just two summits short of his goal of conquering them all.
0:08:40 > 0:08:42Here's the cairn.
0:08:42 > 0:08:46This must be the very top. There we go. Aonach Mor!
0:08:46 > 0:08:49My first Munro!
0:08:49 > 0:08:51Only to 279 go.
0:08:51 > 0:08:54From up here they all look big,
0:08:54 > 0:08:59right from the Cairngorms across to Aonach Beg that one with the snow cap on there.
0:08:59 > 0:09:04These mountains here above Glencoe, they must all be Munros.
0:09:04 > 0:09:07And there's the daddy of them all... Ben Nevis.
0:09:07 > 0:09:10Britain's highest mountain.
0:09:10 > 0:09:131,344 metres.
0:09:13 > 0:09:15For old-fashioned chaps like me -
0:09:15 > 0:09:21and for Mr Munro's benefit - that comes to exactly 4,408 feet.
0:09:33 > 0:09:38The name Ben Nevis comes from the Gaelic for "Mountain of Heaven".
0:09:38 > 0:09:44On a day like today, it certainly feels as though I've climbed towards the gods.
0:09:55 > 0:10:00When first formed, the peaks would have been even more impressive.
0:10:00 > 0:10:04They were once tens of thousands of feet high,
0:10:04 > 0:10:10forming a range of mountains as tall as the Himalayas.
0:10:10 > 0:10:13Ben Nevis would have rivalled Mount Everest!
0:10:17 > 0:10:21The Highlands mark a kind of "crumple zone" forced upwards
0:10:21 > 0:10:24as England and Scotland crashed into each other.
0:10:27 > 0:10:32And all along the southern side of this join, huge volcanic eruptions
0:10:32 > 0:10:35created Snowdonia and the Lake District.
0:10:36 > 0:10:40So what happened to Scotland's Himalayas?
0:10:40 > 0:10:42Where are they now?
0:10:44 > 0:10:49As soon as they were formed, they came under attack... from the weather!
0:10:51 > 0:10:54Snow and ice, wind and rain
0:10:54 > 0:10:59all began to eat away at the rock, cutting these giants down to size.
0:10:59 > 0:11:02THUNDER CRACKS
0:11:08 > 0:11:10And today,
0:11:10 > 0:11:15400 million years later, this attack is still raging.
0:11:31 > 0:11:34Nowhere has more "weather" than Scotland -
0:11:34 > 0:11:38900 billion gallons of rain falls here each year
0:11:38 > 0:11:43and it all collects in thousands of streams and rivers,
0:11:43 > 0:11:47gaining strength and gathering momentum as it goes.
0:11:47 > 0:11:54Then, gravity takes over, and as everybody knows, gravity is irresistible.
0:11:59 > 0:12:04These powerful rivers gouge away at the land as they pour down the mountainside,
0:12:04 > 0:12:09cutting and constantly re-shaping what's left of the Highlands.
0:12:09 > 0:12:13And the biggest Scottish river is this one - the Tay.
0:12:14 > 0:12:18It's over 100 miles long, and by the time it reaches the sea,
0:12:18 > 0:12:23it's carrying more water than the Thames and Severn combined.
0:12:23 > 0:12:26The water in this river has come from all over Scotland.
0:12:28 > 0:12:32It all gets funnelled into this one valley.
0:12:46 > 0:12:52Nothing can resist its power for long, as it pummels and pounds everything in its path.
0:12:52 > 0:12:55And I know just how that feels!
0:13:04 > 0:13:06Some water feature!
0:13:06 > 0:13:08Whoo!
0:13:10 > 0:13:15Like going through the washing machine and the wringer in one go.
0:13:15 > 0:13:18For hundreds of millions of years,
0:13:18 > 0:13:23the weather has slowly taken the mountains apart.
0:13:26 > 0:13:30And the rivers have spread their remains far and wide.
0:13:38 > 0:13:42Today, Scotland's Himalayas have been worn almost flat.
0:13:42 > 0:13:45But where has all that rock gone?
0:13:48 > 0:13:52Well, a lot of it ended up here, and built this...
0:13:52 > 0:13:56Stanage Edge in Derbyshire. It's all millstone grit,
0:13:56 > 0:14:02made from the pulverised remains of those ancient Scottish mountains.
0:14:05 > 0:14:07Today it's part of the Pennines,
0:14:07 > 0:14:12which means that the very backbone of England was made in Scotland!
0:14:15 > 0:14:18Grit stone is tough stuff,
0:14:18 > 0:14:22and full of sharp edges, making it perfect for one job.
0:14:22 > 0:14:26For hundreds of years, maybe back as far as the 12th century,
0:14:26 > 0:14:31millstones have been quarried from this exposed escarpment.
0:14:31 > 0:14:35And the surprising thing is, you can still find them today
0:14:35 > 0:14:39scattered like handfuls of coins right all along this ridge.
0:14:39 > 0:14:43There are around 1,500 of them dotted about the place.
0:14:43 > 0:14:47At two tonnes apiece, these were used for turning grain into flour.
0:14:47 > 0:14:51There are smaller ones as well - grindstones -
0:14:51 > 0:14:54used for giving Sheffield cutlery its cutting edge.
0:15:00 > 0:15:05But the grit stones make it hard to carve out a living up here.
0:15:09 > 0:15:13On these bleak moors, even the plants have it tough.
0:15:17 > 0:15:21The soil here is badly drained and extremely boggy...
0:15:21 > 0:15:23- SQUELCH - It is!
0:15:25 > 0:15:30Clumps of cotton grass break up the great swathes of heather and bracken.
0:15:30 > 0:15:36It's all pretty desolate and yet, if you look a bit closer,
0:15:36 > 0:15:41there are botanical treasures to be found...like the sundew.
0:15:41 > 0:15:44Its rounded leaves are covered in hairs,
0:15:44 > 0:15:46each one of which is equipped with sticky goo.
0:15:46 > 0:15:49It catches insects to supplement its diet.
0:15:49 > 0:15:54The landing's easy, but the taking-off is nigh-on impossible.
0:16:03 > 0:16:08Just one insect can provide enough nutrients to keep this sundew going for months.
0:16:15 > 0:16:21The Pennines stretch for over 200 miles from Derbyshire all the way to the Scottish border.
0:16:23 > 0:16:27This place is very close to my heart.
0:16:27 > 0:16:32Some of my earliest memories are of family trips up here.
0:16:32 > 0:16:34And I guess it's the same for many.
0:16:42 > 0:16:47I was brought up on these Yorkshire gritstones, and it was journeys
0:16:47 > 0:16:51up on to the moors that first fired my love for this landscape.
0:17:02 > 0:17:06These moors are surrounded by some of our largest cities,
0:17:06 > 0:17:09providing a place to escape from the hurly-burly of modern life.
0:17:24 > 0:17:29But nestling beneath the Yorkshire Moors is a very different countryside -
0:17:29 > 0:17:33softer, greener and more fertile.
0:17:33 > 0:17:36The Dales.
0:17:38 > 0:17:44This is limestone country, and here, again, the rock has been used to great effect.
0:17:46 > 0:17:51Swaledale is criss-crossed by walls made from the local stone.
0:17:54 > 0:17:58But you can also use this stone to build something else -
0:17:58 > 0:18:01a picture of the Dales' past,
0:18:01 > 0:18:04revealing an event that shaped the British Isles.
0:18:04 > 0:18:08The stones are literally filled with clues.
0:18:08 > 0:18:10But you've got to rummage a bit
0:18:10 > 0:18:13until you find
0:18:13 > 0:18:17what you are looking for... Here's one, there we are.
0:18:17 > 0:18:19It's a fossil coral.
0:18:19 > 0:18:23But what's a coral doing in the Yorkshire Dales?
0:18:25 > 0:18:29Corals like this only grow in warm, shallow water.
0:18:29 > 0:18:33Today, they thrive on the reefs of Australia and the Caribbean.
0:18:33 > 0:18:38Their fossilised presence here can only mean one thing
0:18:38 > 0:18:43there must once have been a tropical reef right here in Yorkshire.
0:18:47 > 0:18:55You can find fossil corals in Ireland, southern Scotland, the Lake District and Somerset.
0:18:55 > 0:18:56So these ancient tropical seas
0:18:56 > 0:19:00must have covered much of the British isles.
0:19:10 > 0:19:16This landscape is more like the surface of the moon than the Yorkshire Dales.
0:19:16 > 0:19:18It's a limestone pavement.
0:19:18 > 0:19:25Great lumps of rock that interlock like a jigsaw with great fissures in between them.
0:19:25 > 0:19:29The lumps are called clints, and the fissures are called grikes,
0:19:29 > 0:19:35some of which are three or four metres deep, so don't lose your footing!
0:19:37 > 0:19:41This landscape has been created by water.
0:19:41 > 0:19:46It dissolves limestone, sculpting it into these convoluted shapes.
0:19:49 > 0:19:53But there's hardly a stream or river to be seen.
0:19:53 > 0:19:56So where are they?
0:19:56 > 0:19:58- Ready?- Ready!
0:19:58 > 0:20:00Let her go!
0:20:00 > 0:20:02This is where one of those rivers has gone...
0:20:02 > 0:20:08Gaping Gill. One of the largest caves in the British Isles.
0:20:08 > 0:20:10Wood anemones and wood sorrel...
0:20:10 > 0:20:15Oh, but now, nothing - just blackness and shiny rock...
0:20:15 > 0:20:19I see mist coming down, and now it's widening...
0:20:19 > 0:20:24A great cavern with black walls running with water...
0:20:24 > 0:20:27And now the water's running on me! Ah!
0:20:27 > 0:20:31Even more scary. Are we there?
0:20:35 > 0:20:38Am I there? Is that the bottom?
0:20:38 > 0:20:41Ooh! It's like the journey to the centre of the Earth.
0:20:41 > 0:20:45That was unbelievable! I've followed the water all the way down.
0:20:45 > 0:20:48It's like being a pebble thrown into a waterfall.
0:20:48 > 0:20:53And it's the longest unbroken waterfall in Britain
0:20:53 > 0:20:57at 111 metres, that's twice the height of Niagara.
0:20:57 > 0:21:00And boy, did it feel like it?!
0:21:00 > 0:21:04There are several of these monstrous plumes of water
0:21:04 > 0:21:09tumbling down through the rock here and they make a heck of a din.
0:21:09 > 0:21:11Over hundreds of thousands of years,
0:21:11 > 0:21:16they've worn away the limestone to make this enormous cavern.
0:21:28 > 0:21:30And how do we know it's limestone?
0:21:30 > 0:21:34Because just like the dry stone wall, it's got fossils in it.
0:21:34 > 0:21:41There's the coral and down here sea shells, proving this was once underwater.
0:21:41 > 0:21:48And when it floods and the water in here rises 10 metres higher than my head, it's underwater again.
0:21:53 > 0:22:00The tropical seas that submerged Yorkshire for 30 million years eventually receded.
0:22:00 > 0:22:05As our ancient coastline emerged, a new landscape was born.
0:22:05 > 0:22:11If you live in Glasgow, you can nip down to the local park to see what happened.
0:22:11 > 0:22:15Victoria Park is full of trees - well, stumps.
0:22:15 > 0:22:20But they are 300 million years old, and made of stone.
0:22:22 > 0:22:30Judging by the size of these stumps, some of the trees must have been 100 feet tall.
0:22:30 > 0:22:37And what's more, they were lepidodendrons, trees only found in ancient tropical rainforest.
0:22:51 > 0:22:55Britain's ancient rainforest was filled with botanic wonders,
0:22:55 > 0:22:58and ruled by insects.
0:23:03 > 0:23:07Dragonflies filled the air, and some were huge,
0:23:07 > 0:23:11with a wingspan of nearly two feet.
0:23:11 > 0:23:13WINGS FLUTTER RAPIDLY
0:23:19 > 0:23:23And there were giant millipedes, six feet long.
0:23:27 > 0:23:32But these forests left behind more than fossilized insects and tree stumps.
0:23:32 > 0:23:37Their real legacy fired one of the greatest revolutions in our history.
0:23:39 > 0:23:40It was this...
0:23:40 > 0:23:42coal!
0:23:47 > 0:23:51This is the Stobswood open cast mine in Northumberland.
0:23:51 > 0:23:55It's the largest mine of its kind still operating in Britain,
0:23:55 > 0:23:59producing almost a million tonnes a year.
0:23:59 > 0:24:02You need massive machinery to dig a hole this big.
0:24:02 > 0:24:05This one's called the "Ace of Spades".
0:24:05 > 0:24:09The bucket is the size of a family house.
0:24:15 > 0:24:20But this huge hole wasn't entirely filled with coal.
0:24:20 > 0:24:23The valuable stuff is in these seams,
0:24:23 > 0:24:26sandwiched between sandstone and shale.
0:24:26 > 0:24:31And there's the clue as to how wood turns into coal.
0:24:33 > 0:24:39Each band of grey rock marks a time when these forests were flooded by rising seas
0:24:39 > 0:24:42and buried by sand and sediments.
0:24:45 > 0:24:51As this built up, the increasing weight slowly compressed the fallen trees of the forest,
0:24:51 > 0:24:54transforming them into coal.
0:25:02 > 0:25:07It takes a 30ft layer of wood to produce just 3ft of coal...
0:25:07 > 0:25:13so just one seam represents a lot of rainforest and an awful lot of time!
0:25:14 > 0:25:20Multiply that by each coalfield in Scotland, England and South Wales,
0:25:20 > 0:25:23and it shows just how vast the forests were.
0:25:28 > 0:25:33Because ancient Britain sat on the equator 300 million years ago,
0:25:33 > 0:25:39we had the right conditions to grow the raw materials that would fuel the Industrial Revolution.
0:25:45 > 0:25:48But nothing lasts forever.
0:25:49 > 0:25:52The British Isles were about to get a shake-up...
0:25:52 > 0:25:57a chain of events began that would see the tropical forests disappear,
0:25:57 > 0:26:01that would create a beautiful part of the country
0:26:01 > 0:26:04and, eventually, some of our most productive land.
0:26:04 > 0:26:07Time to head to the Southwest.
0:26:13 > 0:26:18Those are the Isles of Scilly down there, 28 miles off Land's End.
0:26:28 > 0:26:31They might look like the Bahamas in summer,
0:26:31 > 0:26:36but come winter, these islands and headlands take a pounding from the Atlantic.
0:26:40 > 0:26:45They are made of granite and we're lucky all this hard rock ended up where it did.
0:26:45 > 0:26:47It's the perfect breakwater.
0:26:47 > 0:26:52Without it, there wouldn't be anything between southern England
0:26:52 > 0:26:54and the fierce Atlantic storms.
0:26:54 > 0:26:59If this barrier wasn't here, Cornwall might be a bit smaller.
0:27:01 > 0:27:07The Scillies are just the most westerly part of a chain of granite outcrops.
0:27:07 > 0:27:13They run through Land's End, Bodmin Moor and up on to Dartmoor.
0:27:15 > 0:27:21Here, they've been slowly sculpted into some of our most recognisable landmarks...
0:27:22 > 0:27:24..the Dartmoor tors.
0:27:32 > 0:27:35But where's all this granite come from?
0:27:35 > 0:27:39Where there's granite, there was once molten rock.
0:27:39 > 0:27:46These tors are the remains of a huge dome of this magma that sat like a boil beneath our ancient skin,
0:27:46 > 0:27:50cooling, slowly, deep underground.
0:27:51 > 0:27:56There must have been massive volcanic activity at the time. What was causing it?
0:27:58 > 0:28:0350 miles away, the coast of North Devon has some of the answers.
0:28:05 > 0:28:11The cliffs at Hartland are made from layer upon layer of ancient sea floor.
0:28:11 > 0:28:17These rocks were all laid down horizontally, as you might expect on the seabed,
0:28:17 > 0:28:23but they've been dramatically re-arranged. Now they're vertical! So what happened here?
0:28:38 > 0:28:40Ooh! That was amazing!
0:28:45 > 0:28:49These rocks here have been concertinaed,
0:28:49 > 0:28:54the horizontal layers ruptured and buckled into a crazy jumble.
0:28:54 > 0:28:57Now, that can only happen under immense pressure,
0:28:57 > 0:29:01the sort of pressure you get when continental plates meet.
0:29:01 > 0:29:07and that's exactly what happened here as Southern Britain crashed into Continental Europe.
0:29:09 > 0:29:13Collisions like this were going on across the globe
0:29:13 > 0:29:20and out of the wreckage emerged one single landmass - a supercontinent called Pangaea -
0:29:20 > 0:29:23and we were slap bang in the middle of it!
0:29:27 > 0:29:34Left sitting near the equator, and basking in the intense heat, Britain got drier and drier.
0:29:34 > 0:29:37Lush, tropical Britain became a desert!
0:29:42 > 0:29:48And the greatest token of this desert past lies in a most unexpected place.
0:29:59 > 0:30:05Devon, glorious Devon - a county that's crisscrossed by sunken lanes,
0:30:05 > 0:30:07like this one at Pitt Farm.
0:30:07 > 0:30:13Cows have been herded up and down this from pasture to milking parlour for centuries.
0:30:13 > 0:30:15Go on!
0:30:18 > 0:30:21They got a shift on, didn't they?
0:30:21 > 0:30:27Devonshire's cows are lucky. The rolling fields here are really special.
0:30:27 > 0:30:32Just look at this grass - rich, thick and tantalisingly sweet.
0:30:32 > 0:30:38It almost makes you wish you were a cow! As any horticulturist knows
0:30:38 > 0:30:42you only get growth like this when you've got decent soil.
0:30:42 > 0:30:46There we are. Look at that - a gardener's dream
0:30:46 > 0:30:50and an important legacy of our desert past.
0:30:51 > 0:30:58This distinctive red colour comes from the iron in the underlying desert rocks
0:30:58 > 0:31:01that's slowly been broken down to form this soil.
0:31:04 > 0:31:09It's strange to think that this, some of our most fertile land,
0:31:09 > 0:31:14owes its origins to one of the harshest periods in our history.
0:31:21 > 0:31:26And with grazing this good, it's no wonder these cows are so productive.
0:31:26 > 0:31:33Here on Pitt Farm, each one of these girls produces about five gallons of milk every day!
0:31:33 > 0:31:38And this is where much of the Devon grass goes...into clotted cream.
0:31:38 > 0:31:45In my humble opinion, one of the greatest contributions Britain has made to the civilized world.
0:31:45 > 0:31:47But there is one contentious point.
0:31:47 > 0:31:50Is it jam first
0:31:50 > 0:31:52and then cream?
0:31:56 > 0:31:58Mmm, that's very, very good.
0:31:58 > 0:32:02Or is it cream first and then jam?
0:32:04 > 0:32:08Oh, it's very difficult. It clearly requires...
0:32:09 > 0:32:12..considerable research.
0:32:12 > 0:32:16I've got the time, the inclination, the clotted cream.
0:32:19 > 0:32:22It is very nice with the jam first.
0:32:22 > 0:32:26You get the strawberries coming through...
0:32:26 > 0:32:30Thank you. It was very nice. Mm!
0:32:30 > 0:32:33You wouldn't have a glass of milk, would you?
0:32:33 > 0:32:37You can have too much of a good thing, you know.
0:32:41 > 0:32:44And the conclusion is...
0:32:46 > 0:32:48..inconclusive.
0:32:54 > 0:32:56One thing is for sure.
0:32:56 > 0:33:02After 80 million years of baking heat, the deserts began to disappear.
0:33:02 > 0:33:04Britain was back on the move.
0:33:04 > 0:33:07We were about to enjoy a much balmier time,
0:33:07 > 0:33:13and to find out more, I need to visit our very own Jurassic coastline,
0:33:13 > 0:33:18that stretches the width of Dorset, from Lyme Regis to Swanage.
0:33:34 > 0:33:38All along this coast, the sea is eating away at the cliffs,
0:33:38 > 0:33:42uncovering clues and scattering them on the beach.
0:33:42 > 0:33:46Every pebble under your feet could be 200 million years old.
0:33:46 > 0:33:50Rocks like these can tell us a huge amount about that time
0:33:50 > 0:33:54and even amateurs like me can find out. Watch this.
0:33:59 > 0:34:02Wow! Look at that...
0:34:02 > 0:34:04an ammonite.
0:34:07 > 0:34:11This animal didn't live in the desert, but in the sea.
0:34:11 > 0:34:18The supercontinent was breaking up and we inherited some superb beachfront real estate.
0:34:21 > 0:34:25Our south coast would have been like the Caribbean.
0:34:28 > 0:34:32These Jurassic seas weren't just filled with ammonites,
0:34:32 > 0:34:36they were home to all kinds of fantastical creatures.
0:34:41 > 0:34:44For the next 70 million years,
0:34:44 > 0:34:50Britain was a tropical paradise of inviting lagoons and endless reefs.
0:34:50 > 0:34:56In these clear, warm waters, a new piece of the British landscape was being created.
0:35:03 > 0:35:06Just as in Yorkshire, millions of years before,
0:35:06 > 0:35:10this new landscape is made of limestone.
0:35:18 > 0:35:22It sweeps in a great arc across Middle England,
0:35:22 > 0:35:26from the Dorset coast, along the Cotswolds, up to Lincolnshire.
0:35:38 > 0:35:45It's easy to follow its path today, because this beautiful stone has been quarried for centuries
0:35:45 > 0:35:52and used to build quaint cottages and city halls from Portland to Ashby-cum-Fenby.
0:35:55 > 0:35:58BICYCLE BELL TINKLES
0:36:00 > 0:36:05The heart of Oxford is built from this butter-coloured stone,
0:36:05 > 0:36:08ornately carved and sculpted as any work of art.
0:36:08 > 0:36:12All this is made from local Jurassic stone
0:36:12 > 0:36:15quarried from no more than a few miles away.
0:36:15 > 0:36:18Over there is the Bodleian Library.
0:36:18 > 0:36:23They've been entitled to receive a copy of every book printed in the UK since 1610.
0:36:23 > 0:36:25They might have mine!
0:36:25 > 0:36:31But I'm not here to look at the books, I'm here to inspect the walls.
0:36:32 > 0:36:35Look at these blocks of stone -
0:36:35 > 0:36:38strong, smooth and durable.
0:36:38 > 0:36:42Stonemasons called it freestone, not cos it was cheap,
0:36:42 > 0:36:48but because it was free of flaws and you could cut it in any direction. But that's not all.
0:36:57 > 0:37:03You see, not only is this Jurassic rock strong enough to be used as building blocks,
0:37:03 > 0:37:07it's also malleable enough to be intricately carved.
0:37:07 > 0:37:09It's the perfect combination.
0:37:10 > 0:37:14You only have to come to Oxford on a day like this
0:37:14 > 0:37:19and it becomes perfectly obvious why they call it the City of Dreaming Spires.
0:37:27 > 0:37:31The masons decorated the buildings with mythical Greek heroes,
0:37:31 > 0:37:34rich benefactors,
0:37:34 > 0:37:37grotesques and gargoyles.
0:37:40 > 0:37:45But little did they know the rock itself held creatures
0:37:45 > 0:37:48more monstrous than any gargoyle.
0:37:48 > 0:37:53And as the quarrymen dug deeper, more secrets were revealed -
0:37:53 > 0:37:57the bones of a giant animal.
0:37:58 > 0:38:01It was 25ft tall, weighed about a ton,
0:38:01 > 0:38:03stood on two legs.
0:38:03 > 0:38:05It was a dinosaur!
0:38:08 > 0:38:14Since these first discoveries, hundreds of dinosaurs have been found in our limestone rocks.
0:38:14 > 0:38:19The British Isles really was the original Jurassic park.
0:38:38 > 0:38:43But while this period was known as the age of the dinosaurs,
0:38:43 > 0:38:48it also marks the arrival of another great group of living things -
0:38:48 > 0:38:53flowering plants like this magnolia, which is one of the most primitive.
0:38:53 > 0:38:57Its ancestors first opened their cup-shaped blossoms
0:38:57 > 0:39:01when the dinosaurs were still about, around 100 million years ago.
0:39:01 > 0:39:07I'm glad it was the dinosaurs that died out and not the flowers.
0:39:13 > 0:39:17Throughout this time, dinosaurs ruled
0:39:17 > 0:39:21from the Isle of Wight to the Isle of Skye.
0:39:21 > 0:39:23SCREECHING
0:39:36 > 0:39:39Then, around 100 million years ago,
0:39:39 > 0:39:45all traces of these magnificent creatures disappeared from our shores.
0:39:49 > 0:39:53It coincided with the greatest event to effect our islands,
0:39:53 > 0:39:58and it left us with perhaps the most famous lumps of rock in the world.
0:39:58 > 0:40:01I'm on my way to see them now.
0:40:14 > 0:40:21The Seven Sisters on the Sussex coast - one of our most spectacular landmarks.
0:40:21 > 0:40:24This is by far the best place to see them.
0:40:24 > 0:40:29They have welcomed home-comers and repelled invaders for centuries,
0:40:29 > 0:40:33but their history goes back much further than that.
0:40:33 > 0:40:36And to discover it, I need to take a closer look.
0:40:42 > 0:40:48Apart from these layers of flint that are embedded in it, this chalk has no distinguishing features,
0:40:48 > 0:40:53nothing to give a clue as to its origins, at least, not to the naked eye.
0:40:53 > 0:40:58But put it under an electron microscope and it comes alive.
0:41:01 > 0:41:07These are the shells and skeletons of tiny sea creatures, trillions of them!
0:41:13 > 0:41:16This whole cliff is one huge fossil bed.
0:41:17 > 0:41:21And that can only mean one thing. 100 million years ago,
0:41:21 > 0:41:24Britain was covered by water, not just by a few feet of it.
0:41:24 > 0:41:28Then the sea level was 300 metres higher than it is today.
0:41:31 > 0:41:36The shallow Jurassic sea rose to cover the land.
0:41:36 > 0:41:42Virtually all of Britain vanished beneath the waves and with it went our dinosaurs.
0:41:51 > 0:41:58The British Isles were to remain at the bottom of the deep for the 30 next million years,
0:41:58 > 0:42:02until one last mega-event forced them back up to the surface.
0:42:02 > 0:42:08The best place to see what happened is on the north coast of Northern Ireland.
0:42:11 > 0:42:18What I'm looking for was created as Britain neared the end of an epic journey across the globe.
0:42:18 > 0:42:24Just 60 million years ago, Britain was drifting towards its present position.
0:42:24 > 0:42:29A journey that had taken it 8,000 miles since England and Scotland
0:42:29 > 0:42:32had first come together south of the equator.
0:42:32 > 0:42:35And there it is.
0:42:47 > 0:42:51The effect on the land couldn't be more eye-catching.
0:42:54 > 0:42:58Rising up out of the sea on the Antrim coast
0:42:58 > 0:43:02is a seemingly man-made playground of stepping stones,
0:43:02 > 0:43:06over 40,000 hexagonal columns.
0:43:10 > 0:43:15This has to be one of the oddest place I've visited on my travels through the British Isles.
0:43:15 > 0:43:18It's the Giant's Causeway.
0:43:18 > 0:43:24Local legend has it that an Irish giant named Finn McCool was responsible for all this lot.
0:43:24 > 0:43:30He was challenged to a contest of strength by another giant living on the Scottish island of Staffa,
0:43:30 > 0:43:32just 80 miles over there.
0:43:32 > 0:43:35So Finn hurled rocks into the sea...
0:43:36 > 0:43:42..building a causeway, so he could reach his challenger and teach him a lesson.
0:43:46 > 0:43:51In truth, the Causeway has a less romantic, but equally violent history.
0:43:54 > 0:44:00The columns were formed when lava exploded onto the surface and rapidly cooled.
0:44:00 > 0:44:06But these eruptions were on a vast scale effecting not just Ireland but Western Scotland too.
0:44:06 > 0:44:12This lava formed most of the Isles of Skye and Mull and the Isle of Staffa,
0:44:12 > 0:44:18where you can still see the same hexagonal columns as the Giant's Causeway,
0:44:18 > 0:44:20here stacked around Fingal's Cave.
0:44:23 > 0:44:26What was causing all this upheaval?
0:44:26 > 0:44:32Something that fundamentally changed the nature of the British isles - the birth of the Atlantic Ocean.
0:44:34 > 0:44:39The Atlantic is so all-embracing, it's difficult to imagine it not being here.
0:44:39 > 0:44:43But for much of our history, it simply didn't exist
0:44:43 > 0:44:48and Western Europe nestled up snugly against North America and Greenland.
0:44:48 > 0:44:51But as the two continents began to tear apart,
0:44:51 > 0:44:54spewing out thousands of miles of lava,
0:44:54 > 0:45:00it drove a powerful wedge between the European and North American plates,
0:45:00 > 0:45:03slowly forcing them further and further apart.
0:45:12 > 0:45:17So 60 million years ago, the Atlantic Ocean was born
0:45:17 > 0:45:22and it's still growing today, albeit slowly, about the rate our fingernails grow.
0:45:23 > 0:45:25It's already 3,000 miles wide
0:45:25 > 0:45:31and increasing by two and a half inches every year.
0:45:31 > 0:45:33As the Atlantic opened,
0:45:33 > 0:45:38Britain once again slowly emerged from beneath the murky waters...
0:45:40 > 0:45:43..but we came up tilted at an angle,
0:45:43 > 0:45:49the North first and the rest following over millions of years...
0:45:49 > 0:45:54slowly revealing more and more of our foundations.
0:46:06 > 0:46:10After the great events that created these foundations,
0:46:10 > 0:46:13they would now be shaped by wind,
0:46:13 > 0:46:16water, ice and ourselves
0:46:16 > 0:46:19into landscapes we recognise today.
0:46:49 > 0:46:55The last part of the British Isles to emerge from beneath the Atlantic was the southeast corner.
0:46:55 > 0:47:02That makes the rocks here, under England's capital city, some of the youngest in the land.
0:47:03 > 0:47:07For the time being, this marks the end of my journey.
0:47:07 > 0:47:11But the geological clock that began ticking on the Isle of Lewis
0:47:11 > 0:47:15nearly three billion years ago is still going strong.
0:47:17 > 0:47:20All around Britain, new rocks are being made
0:47:20 > 0:47:24and some day, that mud down there at the bottom of the Thames
0:47:24 > 0:47:29will become the next layer of bedrock that underpins our islands
0:47:29 > 0:47:35and it's that bedrock that ultimately shapes the very nature of the British Isles.