I have. I don't recall any part of it which captured the same sense of "ik". I have seen docu's of folks going pot-holing and it's deffo not the sport for me.

That said, I don't have an issue with *caves* as such. The french are quite fond of discovering cave networks then turning them into tourist visits, and that's fine, the formations are fascinating and I can see the appeal of being underground but if it means wriggling through holes that small, I'm happy to leave it to the ferrets.