Join a group of cavers on a through trip ? Bar Pot to Stream Passage Pot ? of England's Gaping Gill System.

https://www.youtube.com/watch?v=hEB4XxsNjIw

Filmed in June 2015, the outing was an exchange trip between the South Wales Caving Club and the South Bristol Speleological Society.

Through trip? I was expecting them to come out via Ingleborough Cave 

Followed Tony's link and hit this one as well:

https://www.youtube.com/watch?v=_xduEyXTdgc

Its a seriously good video of the recent rescue practice at Cwmystwyth. Some very good underground footage.