In a rare moment of restraint, Dimwit Flathead scaled back his plans for putting an entire mountain range in the castle, settling for merely a single mountain. The Great Underground Mountain is one of the many awe-inspiring features of Dimwit's castle in Flatheadia, existing entirely underground.

The mountain was crested with a tiny plateau, a man's length lower than the ceiling of the castle. The inspiring view made it easy to see why Dimwit Flathead climbed this mountain with such frequency. (Some quibblers insisted that it's hardly "mountain climbing" to be carried up in a plush sedan chair, but those quibblers were all tortured to death years ago.) Within a grotto near the peak was a shrine to Saint Foobus of Galepath. At the base of the mountain lay the stables which once held the thousands of royal mounts.

To the west of the mountain are the placid waters of Lake Flathead; to the southwest is the vast indoor Great Underground Desert, divided by the verdant Great Underground Woods and Savannah.

SOURCE(S): Zork Zero