0:00:26 > 0:00:31Sunny Llandudno and its magnificent limestone headland - the Great Orme.
0:00:33 > 0:00:36The white pimple on the summit used to be the optical telegraph station.
0:00:36 > 0:00:40Then it became a pub, a hotel, a golf club, radar station,
0:00:40 > 0:00:42then a hotel again.
0:00:42 > 0:00:44And now it's a welcome cafe.
0:00:44 > 0:00:48You see nothing on the Orme is exactly what you think it is.
0:00:50 > 0:00:53I've been told there's a real secret here on the Orme.
0:00:53 > 0:00:56It's an extraordinary story about a mysterious cave
0:00:56 > 0:01:00that has electrified the imagination of everyone who's seen it.
0:01:00 > 0:01:02That's my kind of story.
0:01:06 > 0:01:11Now all I've been told is that the cave is called Ogof Llech - the hiding cave -
0:01:11 > 0:01:14and that it's several hundred feet below the Orme's summit.
0:01:14 > 0:01:17My guide is local cave and mine expert Nick Jowett.
0:01:17 > 0:01:21There's no chance of our getting there by sea. I know, we tried.
0:01:21 > 0:01:24There was too big a swell for us to land.
0:01:24 > 0:01:29Plus we had to make our attempt today because the sea birds are already coming in to nest
0:01:29 > 0:01:31and there's no way we can disturb them.
0:01:31 > 0:01:36Oh, yes and that isn't a path down the slope above - it's subsidence in progress.
0:01:36 > 0:01:40Nothing for it but to enlist the help of two professional climbers and get down by rope.
0:01:46 > 0:01:49Try and keep your body over right, Neil.
0:01:49 > 0:01:53- Yeah. You coming?- I'll wait till you're on the next rope, Neil.
0:01:53 > 0:01:56It's as every bit as unpleasant as I'd imagined!
0:01:56 > 0:01:58- You OK there?- Yep.
0:02:02 > 0:02:05This is a heck of an afternoon's stroll, Nick!
0:02:06 > 0:02:10Slimy rocks, 100 foot above the sea - it's just dreamy.
0:02:10 > 0:02:12- Right.- We're nearly there, Neil.
0:02:12 > 0:02:14Just scramble up into the cave.
0:02:16 > 0:02:18Oh, that's unbelievable!
0:02:18 > 0:02:20That's the last thing I was expecting!
0:02:20 > 0:02:25- It's like a little bit of Yorkminster's been picked up and stuck in this cave!- Absolutely.
0:02:25 > 0:02:31Look at it, it's like, what, half of an eight-sided sort of...
0:02:31 > 0:02:34One, two, three, four, five sides.
0:02:34 > 0:02:42And then there's a semi-circular seat and this is like it's the upright column
0:02:42 > 0:02:46with a circular base of a stone-carved table.
0:02:46 > 0:02:48There would be, you know, a top here.
0:02:48 > 0:02:51So you could come in here and sit around, sit around a stone table!
0:02:51 > 0:02:53A round stone table, yeah.
0:02:53 > 0:02:58The interesting thing, of course, is that this is sandstone and the Great Orme's made of limestone.
0:02:58 > 0:03:01So they haven't just brought it from just outside the cave entrance,
0:03:01 > 0:03:04they've had to have been brought in from elsewhere.
0:03:04 > 0:03:07At the moment we've got no idea where the stone came from.
0:03:07 > 0:03:09Look at this as well - 1853.
0:03:09 > 0:03:11How old is it?
0:03:11 > 0:03:14- Some of the earliest graffiti is on this back wall here.- Uh-huh.
0:03:14 > 0:03:16It looks to me like 1718.
0:03:18 > 0:03:22- What a view as well. - Lovely view out to sea.
0:03:22 > 0:03:27- If you carry on round this, there's a lovely feature I'd like you to have a look at.- Right.
0:03:33 > 0:03:39Lots of the old guide books tell us that there's the face of a man
0:03:39 > 0:03:41- and an owl and a swan.- Carved faces?
0:03:41 > 0:03:43Carved into the stone here.
0:03:43 > 0:03:48I've looked on many occasions. I've certainly never seen an owl and a swan.
0:03:48 > 0:03:50But if you look up here...
0:03:50 > 0:03:53- Yes!- I think you can make that out.
0:03:53 > 0:03:57Yes, you can the see the face. Two eyes. You can see where a nose has been.
0:04:03 > 0:04:05Some people say it's a bishop because it has a mitre.
0:04:05 > 0:04:08Other people say it's a knight with a knight's helmet.
0:04:08 > 0:04:12Other people say it's an angel, so lots of different theories
0:04:12 > 0:04:16and then people draw their own conclusions from what they think that face is.
0:04:16 > 0:04:19It's so dramatic. To me it looks like the head of a cobra.
0:04:19 > 0:04:24You wonder what's going on here. It's obviously meant so much to the person or people that did it.
0:04:24 > 0:04:28- And yet they haven't left anything behind to show why they did it.- No.
0:04:28 > 0:04:30So it all remains a mystery.
0:04:38 > 0:04:41So who built Ogof Llech and when and why?
0:04:41 > 0:04:45The place is a complete conundrum so here's what I'm doing,
0:04:45 > 0:04:48I've sent a small sample of the sandstone away for analysis
0:04:48 > 0:04:50to see if I can find out exactly where it's from.
0:04:51 > 0:04:55One thing I can be fairly certain of, if that graffiti is reliable
0:04:55 > 0:04:59whoever built the cave's interior did so over 300 years ago.
0:04:59 > 0:05:03There must be documents or estate papers or something that can help us.
0:05:03 > 0:05:07So I've started contacting local historians and libraries
0:05:07 > 0:05:11and some interesting names are cropping up in connection with the cave.
0:05:11 > 0:05:12Charles Darwin?
0:05:12 > 0:05:17And there's also talk of an ancient Welsh poem written about the cave that has to be worth a look.
0:05:17 > 0:05:19It just looks like a little church.
0:05:19 > 0:05:20This is frustrating.
0:05:20 > 0:05:23I seem to be getting nowhere fast.
0:05:23 > 0:05:26Is there any news on the stone sample?
0:05:26 > 0:05:28Now that IS interesting.
0:05:28 > 0:05:32But at long last I DO have something positive to report.
0:05:32 > 0:05:33Do you remember this?
0:05:33 > 0:05:36Oh, that's the piece of stone that we picked from the cave.
0:05:36 > 0:05:39Well that surface there, that's where the sample has been taken.
0:05:39 > 0:05:43I sent it off to the British Geological Survey in Nottingham
0:05:43 > 0:05:48and they've got detailed records of all the known sources of stone
0:05:48 > 0:05:51and they cross-referenced it and have come back with this.
0:05:51 > 0:05:57It says the sandstone sample from Ogof Llech compares closely with sandstones from the Gwespyr Quarries
0:05:57 > 0:05:59at Talacre.
0:05:59 > 0:06:00Oh, right. OK. That's just down the coast.
0:06:00 > 0:06:04Probably about 30 miles away.
0:06:04 > 0:06:08Another interesting point from our point of view is the Talacre Quarry
0:06:08 > 0:06:11- was part of the Mostyn family estates.- Oh, OK.
0:06:11 > 0:06:15It says the Mostyn family controlled that quarry as early as the 16th century.
0:06:15 > 0:06:18That gives us now the first hard evidence here
0:06:18 > 0:06:20which is brilliant news.
0:06:20 > 0:06:25So the sandstone sample has given us a specific connection with a family called the Mostyns.
0:06:25 > 0:06:29Who were they and what was their connection with Llandudno?
0:06:29 > 0:06:32Well, they built it - lock, stock and promenade.
0:06:32 > 0:06:36And they owned the Great Orme where the cave Ogof Llech is.
0:06:36 > 0:06:38And there's more.
0:06:38 > 0:06:43On this map of 1849, there's a clearly defined zigzagging path
0:06:43 > 0:06:45all the way to the cave.
0:06:45 > 0:06:50So for a long time, presumably, there was access to getting down there but not any more,
0:06:50 > 0:06:56hence the ropes and all the rest of the stuff that enabled Nick and I to get round there.
0:06:56 > 0:07:02Now there was that poem to Ogof Llech, and very conveniently for me...
0:07:04 > 0:07:11..on page three of the photocopy, we reveal the nicely copperplate date - 1683.
0:07:11 > 0:07:13Now allow me to translate some of this for you.
0:07:13 > 0:07:18"The cave was furnished with skill and taste for Mostyn's heir.
0:07:18 > 0:07:23"A house of rest for the bright Welshman of new walls hewn in stone."
0:07:23 > 0:07:25Get that, new walls of stone.
0:07:26 > 0:07:29"Also, when he goes to sea, he takes his boat.
0:07:29 > 0:07:33"He passes Llandudno and to fishing devotes himself."
0:07:33 > 0:07:39"Thence to the shore to his abode, the cheerful cave daintily equipped
0:07:39 > 0:07:44"Stones and curious engravings on the walls and stones serving as tables and seats
0:07:44 > 0:07:48"and a round table of hewn stone in the grotto is also preened."
0:07:48 > 0:07:50So what are we dealing with?
0:07:50 > 0:07:55What we have is a cave fitted out as some kind of fishing lodge.
0:07:55 > 0:07:59And it's something to do with the heir of the Mostyn estate
0:07:59 > 0:08:00and we've got a date -
0:08:00 > 0:08:02this is happening around 1683.
0:08:04 > 0:08:06So who was this guy, Mostyn heir?
0:08:06 > 0:08:11Well, in 1683 the lord of the manor, if you will was Roger Mostyn
0:08:11 > 0:08:14and his heir was Thomas.
0:08:14 > 0:08:16This book is a history of the Mostyns.
0:08:17 > 0:08:19And sure enough...
0:08:19 > 0:08:21Sir Thomas Mostyn.
0:08:23 > 0:08:26This is Mostyn's heir.
0:08:29 > 0:08:34For centuries Ogof Llech has excited and puzzled off who have seen it or have heard about it.
0:08:34 > 0:08:38Have we, at long last, solved the riddle of who built it and why?
0:08:38 > 0:08:43I certainly think we've uncovered a snapshot of one period in the history of this mysterious cave.
0:08:43 > 0:08:46But is there more to unravel here?
0:08:46 > 0:08:50You bet there is. Nothing in the Orme is quite what it seems.
0:08:54 > 0:08:57Subtitles by Shoma Mazumder Red Bee Media Ltd
0:08:57 > 0:08:59E-mail subtitling@bbc.co.uk