Watch the clip 4.32

Imagine: it's pitch dark. Only your head is above water. You are squeezing through a narrow gap just four foot across. And you're 20 metres underground.

The stuff of nightmares for some; a good day out for others. Dive into the belly of the earth: find one of Wales's many clubs and go caving!

What do you need to Get Started? What are the Must Have tools of the trade? We've got a load of Trivia and some useful Links to help you find out more.