Originally posted by Peter Nutkins Tako - did you ever go to the Blue John Mines? I am thinking of nipping over and having a look around
There are four show caves in the same valley and I have been in them all several times (although the last time was back in the early 80's). Each one is unique in it's own way but only two were mined for the Blue John semi-precious stone. They are Blue John Cavern and Treak Cliff Cavern, while Speedwell Cavern and Peak Cavern have a different history but are interesting nonetheless. My personal favourites were Peak and Treak Cliff.
Here's a brief synopsis from memory (with a bit of Googling) but bear in mind that it is 30+ years since I last visited the caverns so things may have changed a bit.
Blue John Cavern
A vertical cavern with very steep staircases, climbing back out requires a lot of effort and in some places the walls and roof are very close to the staircases which can be claustrophobic for some people.
Speedwell Cavern
This is a former lead mine and the journey to the actual cavern itself is via the 200 year old mining tunnel which is partially flooded and thus the trip is completed in boats. Each boat has a guide who lies on his/her back on the rear of the boat and propels it along the tunnel by placing their feet on the roof of the tunnel and 'walking' the boat along (it would appear that they may be using electric motors on some boats now). The cavern was discovered when the miners broke through the wall while digging out the lead ore. It is quite an impressive space and contains the 'Bottomless Pit' which obviously is not 'bottomless' but is pretty deep. It is estimated that the pit was originally around 490 ft (150m) deep but the miners used the hole to dump the spoil from their mining operations and it is now only 66 ft (20m) deep. There is only the single cavern so after having a look around it's back onto the boat for the return journey. Time in the main cavern can be limited at peak visitor times as there are obviously other boats trying to bring visitors in too and there is only one place in the tunnel where boats can pass each other.
Treak Cliff Cavern
This cavern was the original source of the Blue John stone and it still contains the largest single piece of Blue John yet to be discovered (worth several million Pounds) but it cannot be removed as it is supporting the roof of the grotto! This is another vertical cavern, but with a twist. Your senses tell you that you are inside a hill and therefore must be going down inside it but when you come out of the exit you discover you are 2-300 feet higher up the hill than where you went in. The whole cavern is a series of small galleries and grottoes and each is spectacular in terms of the geology on display, stalagmites, stalactites and flowstone adorn every surface. It really is a place of outstanding natural beauty and my favourite of all the caverns.
Peak Cavern
This cavern has an amazing history and I like it for the social/historic aspects as much as the geological marvels it contains. The initial cavern in the series (and therefore the mouth of the cave) was originally known as the Devil's Arse and the first recorded use of this name dates back to 1586! It was named for the flatulent noises that emanate from the cave mouth when flood water is draining out of the cave system. The original village of Castleton was actually built inside the mouth of the cave and the whole village was based on rope making. None of the buildings remain but there are displays of the rope making equipment in the cave mouth. The cave mouth has also been used for things like rock concerts and even as a cinema. It is the longest cave system in the Peak District and the mouth is the largest cave opening in the UK. Apparently the 'show cave' section is not as long as it used to be as several sections have been closed to the general public for some reason (probably 'elf 'n' safety') but the cave system extends far beyond the current 'end' and in fact new discoveries have been made that extend the cave system even further including the discovery of the Titan Shaft, a vertical crack in the rock that descends for 464 ft (141.5 m) making it the deepest 'pitch' in Britain. Talking of cracks in the rock, there is one in the roof of one of the caverns that used to be part of the show cave section (and may be still) that has a rather dramatic and sombre history. Sitting on top of the hill that has the cave at the bottom are the ruins of Peveril Castle which were built sometime between 1066 and 1086. In the 'keep' to the castle was an 'oubliette' (a French term meaning 'forgotten place') which was basically a hole in the ground into which miscreants and wrong-doers were dropped to be 'forgotten' (a brutal form of capital punishment). During the early explorations of the Peak Cavern system cavers came upon a large grotto and were horrified to discover piles of human bones with no apparent explanation of how they got there. Further research revealed the truth, The oubliette was in fact over a crevasse that led directly into the roof of the grotto. The poor victims who were thrown into the oubliette would have bounced down the crevasse and then plummeted from the roof of the grotto onto the floor of the cave below. If they weren't killed by the fall they would have certainly suffered multiple broken bones (as shown by the remains) and would then have died a slow and painful death of thirst or starvation in the absolute blackness of the cave (a gruesome thought).
I can highly recommend a visit to anyone in the area and would love to go back to see how things have changed. I still have some photos (on slides) taken in the various caverns.