Chronicles of Embyur
The Floating Mountains, aptly named for being giant floating asteroid sized chunks of Floatstone, only hover above water, and tend to orbit a continent. The Dwarves have managed to pioneer a way to mine the floatstone and use it to keep their Air Ships afloat. One particular floating mountain, simply called “The Hearth” is the center of Dwarven government.
The mountains are never in one place for very long, as they continuously move around the coasts of Embyur. It takes roughly 20 years for a mountain to make one full orbit.
Some say that the Floating Mountains are the origin of Dragons, but the Dwarves claim that is not the case.