You learn something everyday! I knew there was plenty of caving in the area, but I'd never heard of Swildons Hole! I'll have to find it and take a look (and a photo). Mind you tales like this put me off having a go:
http://cavingnews.com/20120423-how-wrong-a-swildons-hole-short-round-trip-can-go
I get mildly claustrophobic (incident as a kiddie that I've never managed to completely get over) which is strange as I was quite happy to wear Breathing Apparatus and fight confined space fires during my time in the RN.
I went down swildon's several times in decades gone by. Cold, dark and wet. Mostly spacious, but the occasional tight squeeze, plus a few flooded passages if you go far enough. I'm no claustrophobe but I don't see the attraction any more!
Now, Box mines to the east of Bath are interesting. Literally a maze in 3 dimensions , something like 60-70 miles of twisting passages. Lots of stories of groups getting lost in the dark down there, but with an organised group you can see the highlights : The "cathedral" cave is spectacular, the abandoned mine working equipment is fascinating (minecarts on rails, cranes, etc), and the sheer scale of the place takes your breath away.
Don't go underground alone!
