0:00:10 > 0:00:13The coast of South West Wales.
0:00:13 > 0:00:18Our earliest ancestors came to the edge of our islands
0:00:18 > 0:00:21for sustenance from land, sea and sky.
0:00:22 > 0:00:27But this cathedral of the elements didn't only nourish their bodies,
0:00:27 > 0:00:29they also found succour for the soul.
0:00:32 > 0:00:35Far on the horizon lies the vanishing point
0:00:35 > 0:00:36between the sea and sky.
0:00:36 > 0:00:40Out there, it seems as if the heavens and the earth meet.
0:00:40 > 0:00:43No wonder then that natural "walkways to eternity",
0:00:43 > 0:00:46like this one, where the land snakes out into the sea,
0:00:46 > 0:00:51are special places with spiritual power for pilgrims and pagans alike.
0:01:21 > 0:01:24Our journey continues, heading for Anglesey,
0:01:24 > 0:01:27starting at Worm's Head in Gower.
0:01:31 > 0:01:35These long fingers of land on the western edge of Britain
0:01:35 > 0:01:37reach out to caress the Irish Sea.
0:01:41 > 0:01:47Gower was the UK's first designated Area of Outstanding Natural Beauty, and at the very tip
0:01:47 > 0:01:53of the Gower Peninsula lies this remarkable headland - Worm's Head.
0:01:53 > 0:01:58Viking's coined its name "ormr" from the Old Norse for serpent.
0:01:58 > 0:02:01I can see why that green spine of land reminded the Vikings
0:02:01 > 0:02:04of a serpent reaching out to sea.
0:02:04 > 0:02:08Those same Norsemen buried their dead in tombs they built
0:02:08 > 0:02:10over there on Rhossili Down.
0:02:10 > 0:02:14Who would dare disturb the spirits of their departed
0:02:14 > 0:02:16with such a fierce beast guarding the shore?
0:02:18 > 0:02:22Even today, you've got to be brave to take on the Worm's Head.
0:02:22 > 0:02:24The scramble across the jagged causeway
0:02:24 > 0:02:28that connects it to the mainland isn't for the faint-hearted.
0:02:28 > 0:02:31I've got to read the tides right - the currents that come swirling in
0:02:31 > 0:02:36across the rocks can easily cut you off, or wash you away.
0:02:40 > 0:02:43You can't afford to hang around.
0:02:43 > 0:02:46One adventurer who got himself marooned out here
0:02:46 > 0:02:48was the poet Dylan Thomas.
0:02:48 > 0:02:53He told tales of being trapped on the rocks by the rising tide as darkness fell.
0:02:56 > 0:02:58Now it gets really tough.
0:02:58 > 0:03:02Just as I need to get a move on, the landscape and the elements are against me.
0:03:05 > 0:03:08Once you've scrambled along the rocks of the low neck,
0:03:08 > 0:03:12you reach a jagged arch, cut by the sea clean through the body of the beast.
0:03:12 > 0:03:16It takes you to the outer head - the loneliest tip of Gower.
0:03:17 > 0:03:21They call this the Devil's Bridge, and I'd love to cross over and carry on,
0:03:21 > 0:03:25but I'm going to leave that little slice of heaven to the birds.
0:03:25 > 0:03:28I'm here in May, and at this time of year,
0:03:28 > 0:03:30the tip of Worm's Head is out of bounds
0:03:30 > 0:03:33because the seabirds are busy nesting.
0:03:35 > 0:03:37I'm glad to get a head start on the tide.
0:03:37 > 0:03:42It's scary how fast the sea rushes in to make this an island once more.
0:03:47 > 0:03:51But there'll be other great walkways into the sea to explore
0:03:51 > 0:03:54as I venture westward along the Welsh shore.
0:03:56 > 0:04:00Worm's Head is just a tiny little snake of land poking its head
0:04:00 > 0:04:03out of the Gower Peninsula, which itself
0:04:03 > 0:04:08pokes out like a pimple on the face of the South Wales coast.
0:04:08 > 0:04:10But this is no unsightly blemish,
0:04:10 > 0:04:16more a site of serene beauty scraped clean by the last ice age.
0:04:25 > 0:04:29We continue our journey westward along Carmarthen Bay.
0:04:31 > 0:04:36Crossing the water into Pembrokeshire, Tenby's sweeping golden beaches
0:04:36 > 0:04:40are just a taste of the majestic shoreline that awaits us.
0:04:40 > 0:04:47Some of the best surfers in the world are drawn to open, wind-blown bays like Freshwater West.
0:04:54 > 0:04:58Hi, I'm Kirsty Jones, I'm a professional kitesurfer.
0:04:58 > 0:05:01I'm Kitesurf World Wave Champion and I've come to Freshwater West
0:05:01 > 0:05:05to train for my next World Cup competition.
0:05:06 > 0:05:09It's my favourite beach to come surfing.
0:05:09 > 0:05:14It's a world-class surfing break and it's also really great for kitesurfing.
0:05:15 > 0:05:19It's a really special place for me because that's where my roots are from
0:05:19 > 0:05:23and it's always nice to come back, even though I travel all over the world.
0:05:26 > 0:05:28OK, here we go.
0:05:29 > 0:05:33I'm going to hit the wave on this one!
0:05:33 > 0:05:40Kitesurfing is using a big power kite to pull you along on the water,
0:05:40 > 0:05:42and you can do tricks, you can do jumps.
0:05:42 > 0:05:44I'm going to do a little grab now.
0:05:44 > 0:05:49You can just cruise along on the water. It's just an amazing sport.
0:05:57 > 0:05:59I'm going to go for a forward loop now.
0:06:06 > 0:06:09Freshwater West is just amazing when it's like this.
0:06:16 > 0:06:19There's something really special about
0:06:19 > 0:06:25the feeling of the sea air and the sea coming back to Wales.
0:06:25 > 0:06:26I just love it.
0:06:32 > 0:06:36Across St Bride's Bay is the tiny harbour of Solva.
0:06:36 > 0:06:39We're nearing the western edge of Wales.
0:06:39 > 0:06:44St Davids is Britain's smallest city with Wales's biggest cathedral.
0:06:44 > 0:06:48The nation's patron saint established a monastery here in the 6th century,
0:06:48 > 0:06:54when the sea was a religious highway spreading the word around early Christian Britain and Ireland.
0:07:01 > 0:07:05Pembrokeshire has Britain's most coastal national park,
0:07:05 > 0:07:10a glorious shoreline that you can walk from beginning to end
0:07:10 > 0:07:14enjoying a coast path 186 miles long.
0:07:14 > 0:07:19It helps to get your walking boots on to find the surprises tucked away along this shore.
0:07:21 > 0:07:24Like here, at Abereiddi.
0:07:26 > 0:07:29The locals call this place the Blue Lagoon,
0:07:29 > 0:07:31and its aquamarine colour
0:07:31 > 0:07:34gives it the look of a tropical pool, but it's far from natural.
0:07:36 > 0:07:42Now it's a playground for divers and coasteers, but this place is a clue
0:07:42 > 0:07:47to an industrial boom that happened here more than 100 years ago.
0:07:47 > 0:07:50It's not just the sea that's been eating away at this coast.
0:07:50 > 0:07:54The locals have done their share of nibbling too.
0:07:54 > 0:07:58This was a slate quarry that once employed around 100 workers.
0:08:00 > 0:08:05And just along the coastal path, another giant hole in the ground.
0:08:05 > 0:08:09An exceptionally hard stone - dolerite - was blasted out
0:08:09 > 0:08:13of the cliffs here, an ideal material for buildings and roads.
0:08:18 > 0:08:20The rock was hauled a short distance by rail
0:08:20 > 0:08:23to the tiny harbour at Porthgain.
0:08:25 > 0:08:29The village is still dominated by enormous brick hulks.
0:08:29 > 0:08:34Here the stone was crushed and graded in five separate bunkers,
0:08:34 > 0:08:37then it cascaded down a loading chute into boats
0:08:37 > 0:08:39waiting at the quayside.
0:08:40 > 0:08:46Today, you see just the odd boat going in and out of the harbour, fishing for crabs and lobsters.
0:08:46 > 0:08:51But when the quarry was going full tilt, the company had six steam coasters and at one time there were
0:08:51 > 0:08:57100 other vessels, all registered at the port, and they're not entirely forgotten either.
0:08:57 > 0:09:01The nameplates of many of them are inside the pub, nailed to the walls and above the tables.
0:09:03 > 0:09:08A remarkable industrial operation dominated the surrounding area
0:09:08 > 0:09:10right up until the 1930s.
0:09:10 > 0:09:12Unearthing this lost world of endeavour
0:09:12 > 0:09:18is a bit of archaeology anyone can do, so much still remains.
0:09:28 > 0:09:33The Welsh coast is a fertile shore for the making of myths.
0:09:33 > 0:09:37Here, legend tells of a city lost to the sea -
0:09:37 > 0:09:40Cantre'r Gwaelod, the Welsh Atlantis.
0:09:44 > 0:09:47And then you come to Porth Oer.
0:09:47 > 0:09:51Here, there's more than a grain of truth in a local claim to fame.
0:09:51 > 0:09:56Alice is on a mission to solve the riddle of the Singing Sands.
0:09:56 > 0:10:00If you believe its name, this beach isn't just heavenly to look at,
0:10:00 > 0:10:03it's also rather wonderful to listen to.
0:10:03 > 0:10:06It's called the Whistling Sands.
0:10:07 > 0:10:14It's not the wind that's whistling, supposedly it's the sand itself that squeaks.
0:10:14 > 0:10:18To get to bottom of it, I'm joined by our acoustics expert David Sharp
0:10:18 > 0:10:19from the Open University,
0:10:19 > 0:10:23who'll be listening for the special music of this place.
0:10:23 > 0:10:25And coastal scientist Rod Jones,
0:10:25 > 0:10:29who'll be looking for the squeak in the sand.
0:10:29 > 0:10:33Listening to the sound of the beach can be a bit hit and miss.
0:10:33 > 0:10:36If it's been a very high tide or it's rained, you'd be out of luck.
0:10:36 > 0:10:41But on a dry, sunny day like this, we should hear the squeak underfoot.
0:10:42 > 0:10:45- Hi David, how are you? - Hello, I'm fine, thank you.
0:10:45 > 0:10:50Now squeaking sand, I'm getting a tiny squeak as I'm walking along but it's very quiet.
0:10:50 > 0:10:54OK, well, just try scuffing your foot through quite hard and see what happens.
0:10:54 > 0:10:58Why don't we walk along a little bit and see if we can get that...
0:10:58 > 0:11:01- SQUEAKING - Oh, there we go. - Oh, that was a good one.
0:11:01 > 0:11:04- This looks quite mad.- That's it.
0:11:07 > 0:11:10Brilliant, I'm getting it really nicely on the screen.
0:11:10 > 0:11:12That's really squeaking!
0:11:15 > 0:11:17I've never heard that before on a beach.
0:11:19 > 0:11:22But we need more feet for the full effect.
0:11:22 > 0:11:28Quiet please, we are recording the Squeaky Beach.
0:11:28 > 0:11:29Yes, come on.
0:11:29 > 0:11:31We'll make a line, I think.
0:11:31 > 0:11:35What we probably need to try to do is to get in step.
0:11:45 > 0:11:50- How did that sound, David? - Oh, it sounded excellent. We've got a really good recording.
0:11:50 > 0:11:53And is this beach unique in making this sound?
0:11:53 > 0:11:55Well, it's not unique.
0:11:55 > 0:12:00There are around 30 beaches in the UK that will have these properties,
0:12:00 > 0:12:02but this is one of the better ones.
0:12:02 > 0:12:06There's a good chance you're close to a whistling beach,
0:12:06 > 0:12:09particularly on the west coast.
0:12:09 > 0:12:11But why aren't there more?
0:12:11 > 0:12:14What makes these beaches special?
0:12:14 > 0:12:18I'm with coastal scientist Rod Jones
0:12:18 > 0:12:21to find out what makes some sand sing.
0:12:23 > 0:12:27What is it that makes the sound at a particular beach special?
0:12:27 > 0:12:28Why isn't all sand the same?
0:12:28 > 0:12:33Well, sound is affected by the energy of the environment where it sits.
0:12:33 > 0:12:37So you've got your waves coming in and that's sorting the sand,
0:12:37 > 0:12:40and it's taking some grains and pulling them offshore,
0:12:40 > 0:12:43and others it's pushing to the top end of the beach.
0:12:43 > 0:12:47And you've also got the process of wind, so when the tide's out,
0:12:47 > 0:12:50these sands will dry and the wind will blow across them
0:12:50 > 0:12:54- and blow the finer particles up to the top of the shore.- Right.
0:12:54 > 0:12:57And the balance of the wave energy, wind energy,
0:12:57 > 0:13:01and the supply and grain size of the sediments that you've got
0:13:01 > 0:13:04at the back there, will define what the particle size
0:13:04 > 0:13:07and characteristics are of the beach sediment.
0:13:08 > 0:13:12How the wind and waves sort the sand depends on the shape of a bay.
0:13:12 > 0:13:14We compared samples from two different beaches,
0:13:14 > 0:13:20from here at Whistling Sands and from Criccieth nearby.
0:13:20 > 0:13:24Right, shall we try this sand first? Which is from Criccieth.
0:13:24 > 0:13:26If I just zoom in on it...
0:13:27 > 0:13:31So, large grains and also a variety of different grain sizes as well.
0:13:31 > 0:13:33- And shapes as well.- Yeah.
0:13:33 > 0:13:37You can actually see little particles of slate there,
0:13:37 > 0:13:39as well as quartz and a lot of other things.
0:13:39 > 0:13:41It's a very varied sort of sand.
0:13:41 > 0:13:45OK, shall we have a look at the sand from Whistling Sands now?
0:13:45 > 0:13:49Let's just compare it with the last one and see just how different it is.
0:13:50 > 0:13:52Now that looks very different.
0:13:52 > 0:13:53It is, isn't it?
0:13:53 > 0:13:57The other one was much more varied in terms of grain size,
0:13:57 > 0:14:01whereas this one seems to be much more dominantly composed of quartz.
0:14:01 > 0:14:05- And it's much more uniform. - Yes.- In terms of size of grains.
0:14:05 > 0:14:09They're quite well rounded, which means they will stack well together.
0:14:09 > 0:14:11They've been sorted down,
0:14:11 > 0:14:15a lot of the coarser and the finer fraction have been lost.
0:14:15 > 0:14:18So wind and waves here have sifted the sand
0:14:18 > 0:14:23into amazingly uniform, well-rounded particles.
0:14:23 > 0:14:26But how does that produce a squeak?
0:14:26 > 0:14:30David's come up with a super-size model of the sand grains.
0:14:30 > 0:14:32David, what are you doing?
0:14:32 > 0:14:35OK, well, what we've got here is
0:14:35 > 0:14:38normal sand found on most beaches, not regular at all.
0:14:38 > 0:14:42And what we've got here is our singing sand, with lots of
0:14:42 > 0:14:46grains of the same size and all very well rounded.
0:14:46 > 0:14:50When you kick your foot through the sand, you cause it to shear.
0:14:50 > 0:14:54- That means, you cause layers to rub across each other.- Right.
0:14:54 > 0:14:57Now let's have a look what happens with the normal sand,
0:14:57 > 0:15:01and you can see that the grains just move up and down,
0:15:01 > 0:15:04all at different times, at different rates.
0:15:04 > 0:15:08With the singing sand, if you kick your foot through that,
0:15:08 > 0:15:13what happens is that the grains all move up and down at the same time.
0:15:13 > 0:15:15- They all move together.- Yeah.
0:15:15 > 0:15:17So why does that produce a squeak?
0:15:17 > 0:15:21Well, it's actually the whole layer moving up and down
0:15:21 > 0:15:24and the whole surface then acts a bit like a loudspeaker,
0:15:24 > 0:15:28vibrating and causing pressure changes in the air above,
0:15:28 > 0:15:29which we hear as sound.
0:15:29 > 0:15:33SQUEAKING
0:15:33 > 0:15:35And not just any sound.
0:15:35 > 0:15:39David's had time to analyse the squeaks he recorded to see if
0:15:39 > 0:15:44the beach is as musical as its nickname, Whistling Sands, suggests.
0:15:44 > 0:15:49The interesting thing is the regularity in which we get these pressure changes,
0:15:49 > 0:15:54so we get these increases in pressure happening at very regular intervals,
0:15:54 > 0:15:57and that's all caused by the sand vibrating up and down,
0:15:57 > 0:15:59just like we saw with the balls,
0:15:59 > 0:16:02And that gives us this pitched sound, like a musical note, almost.
0:16:02 > 0:16:06We can actually demonstrate that, if you want to just try
0:16:06 > 0:16:09- singing some notes into the microphone, we'll record that.- OK.
0:16:09 > 0:16:13- OK, here we go. Right, off you go. - # Ahhhh... #
0:16:13 > 0:16:16SHE SINGS REGULAR NOTES
0:16:19 > 0:16:20OK, that's brilliant.
0:16:20 > 0:16:23If we zoom in on one of those...
0:16:23 > 0:16:26And again, yes, you can see the regular pattern,
0:16:26 > 0:16:28you've got this regular repetition
0:16:28 > 0:16:31of these increases and decreases in air pressure.
0:16:31 > 0:16:35And it's this regular change that gives us the sense of pitch.
0:16:35 > 0:16:39Unlike most sand, this sand actually sings.
0:16:39 > 0:16:40It really does sing, yeah.
0:16:42 > 0:16:45Scientists are starting to explain the sound of the sands,
0:16:45 > 0:16:51but there remains a magical quality to this place that's hard to define.
0:16:51 > 0:16:55I love the fact the Singing Sands are still something of a mystery,
0:16:55 > 0:17:00and it's a puzzle that's played out along the beaches of our coast,
0:17:00 > 0:17:02in the sand under our feet.
0:17:11 > 0:17:16The golden sands and clear waters of Llyn have a majestic backdrop -
0:17:16 > 0:17:18the imposing mountains of Snowdonia.
0:17:18 > 0:17:22And facing them across the water, Anglesey,
0:17:22 > 0:17:26the island known as Mon Mam Cymru - the mother of Wales.
0:17:27 > 0:17:32On its western edge is Llanddwyn Island, home of Saint Dwynwen,
0:17:32 > 0:17:35the patron saint of Welsh lovers.
0:17:36 > 0:17:39Which brings me to my final destination - Llangwyfan.
0:17:43 > 0:17:47I'm on the causeway leading out to the Church in the Sea.
0:17:52 > 0:17:56This is Llangwyfan, the church of Saint Cwyfan.
0:17:56 > 0:17:59The Irish knew him as Saint Kevin,
0:17:59 > 0:18:03and he was from Glendalough, not far from the stretch of Irish coast
0:18:03 > 0:18:05directly across the water from here.
0:18:10 > 0:18:14There's been a church on this site since at least as early as 1254.
0:18:14 > 0:18:17It was extended in 14th and 15th centuries
0:18:17 > 0:18:20so it wasn't always the humble building that's here now,
0:18:20 > 0:18:24because back in the day, there was a lot more land out here than there is now.
0:18:27 > 0:18:31Over the centuries, the sea eroded this site
0:18:31 > 0:18:34until the graves started to fall into the water.
0:18:34 > 0:18:37So now the church sits here on a tiny promontory,
0:18:37 > 0:18:41that, just like Worm's Head where my journey started,
0:18:41 > 0:18:44becomes an island at high tide.
0:18:54 > 0:18:58Subtitles by Red Bee Media Ltd