My favorite location for a dungeon has always been in the mountains. I've ran in valleys and on island but there's nothing so satisfying as the isolation of a mountain to the game. Then there's the weather. One minute it's sunny and 95 degrees, the next it's snowing and the temperature is dropping down below freezing; wind rakes your body and rain stings your flesh. The weather is unpredictable, devastating, and I love it!
The monsters you can throw from a mountain top are more fun too! In deserts you have Jinn, Salamanders, and all that Dark Sun flavor you can ask for; while on islands you can throw in dinosaurs, Sahuagin, and all manner of amphibious life but none of it compares to the mountain. On the mountain you have dragons, wayverns, orcs, trolls, and every nightmare that haunted your dreams as a child. You have redneck trees and men squealing like pigs. You have precipitous falls, hidden chasms, rapids, waterfalls, flooding rivers, hollows, dells, and caverns pocketing the mountain. Everywhere you go the environment, the very mountain under your feet, is trying to kill you. And then, then if you're lucky, you get to the dungeon.
I love mountains!
Read Something Positive for more awesomeness like the above!