The Sea of Stars
An entire mountain range suspended in the air. The population of this land varies above-ground, but bellow-ground it is almost entirely dwarvish. The dwarves use gliders to move between mountains, and have built incredible hanging bridges wherever possible to join the mountains together.
Culturally, think more India than Europe. Home of one of the best magic colleges around, which uses an entire mountain for its grounds, although there would be less than a thousand students. Each one works in an enormous space.