Mechanus is the home of Kiptar.
Mechanus appears to be made entirely of gears, floating in space, continually turning and meshing together, giving it the appearance of a giant mechanical world. Gravity is considered to be toward the gears, making it harder for visitors to get accustomed to it, although creatures that naturally fly tend to have less trouble in the 3-dimensional environment. The gears range from a few inches to over a mile across and cannot be damaged by mortal means.
Mechanus was created when Kiptar was born. It was spawned from its desire to have a place to call its home. Divine energy took that desire and spontaneously shaped Mechanus. Later, Xa'an entered briefly and conversed with Kiptar before leaving.
Mech Swarms are the only current residents of Mechanus, they are everywhere in it.