I was reminded of this topic while watching 'Secret Britain' - watching smiley Ellie go down into deep caves whilst at the same time admitting to claustrophobia. I could and should never do it as a panic attack would surely ensue.

By chance I caught a R4 programme this morning presented by Robin Ince
Hollow Earth: a travel guide - only about 28mins long.
"Virtually every ancient culture, and most religions worldwide, have shared a belief in some sort of mysterious subterranean world, often inhabited by strange and powerful creatures. To the Greeks and Romans it was Hades. To many early Christians, Hell was conceived as a fiery pit deep in the centre of the earth, a scene most elegantly depicted by Dante in his Inferno...."

"can't even look at it" - that's ringing a big bell :)
I guess we'll reduce our chances of being eaten by sleepy bears and other large sharp-toothed animals. We're not letting millions of years of evolution go to waste, even if our gut feelings are wasted because Britain's a bit tame these days. If we go abroad somewhere with bears and rabid bats it'll serve us well!