I think snuffy's right about Tre- and Pol- and Pen-. Tré means village, pen means end, like a peninsula, and pol, well, I've no idea about pol. They are all place name parts, though. That's what I'm going with, unless my Cornish voice teacher tells me differently when I see him next.

ciarili

btw, I'm a caver with batstickers on my car and a subscription to Bat Conservation Int'l, so your handle has me curious. You a caver too, or just pale and tragic?