I've been looking on the Net for info and all I can find are general descriptions of the cave and a definition (with pictures) of blue john. I have no idea what the entrance looks like or the general layout of the cave system. The most I found was a story by Arthur Conan Doyle and I've read enough of his stories that I'd rather not rely on his research.

I've been there AGES ago.
It must have been when I was about 8 or so with my family.
There's like a big open cast bit which you can walk freely around and then a cavern.

I can remember grabbing a load of rubble from the open cast section & sneaking it out of the place. Some of it was raw blue john & I thought it was as precious as diamonds at the time.

Also, there was a funny wishing well thing (so my memory serves) in a bit of grassland that had a concealed lever hidden in it somewhere. The lever controlled the power that fed the lighting in the mines. You could actually throw the switch & turn all the lights off for the mine.

It MUST have changed now though. I cant remember any more than that. I'm really sorry.