Elves, see. They’re just not suited to traipsing around deep dark dungeons far underground. Down there, the closest they’ll get to a tree is if their hair gets tangled up in the roots of some aged oak or whatnot. Dungeons just aren’t a place for these lithe, dainty faery folk with their delicate ways and green-friendly recycling policies.
No, dungeons aren’t good for Elves. They’re dark. claustrophobic places full of icky stuff that likes nothing better than to munch on their vegan flesh. An Elf in a dungeon is like a bird underwater. Unless it’s a pengiun, of course. Pengiuns are the Drow of the bird world. But I digress.
Elves like sky and light and trees and cute little bunny rabbits. They populate stories by Enid Blyton and think that anything larger than a toadstool is to be avoided at all costs. There’s a reason why elves can find secret doors easily and have a high Dexterity; they’re all cowards at heart who’d much rather hide under a leaf than confront evil underground.
Don’t you believe it!
Dude, Elves in Dungeons rock 
You don’t want to know where she got the sword from. Really, you don’t.