Mechanus

Mechanus, also known as Nirvana or the Great Clockwork City, is the home city of the Modrons. The Avatar of Primus resides here, enacting the will of Primus and passing on his orders to the Modrons. The city is known for the forging of arcane items.

Description
This city is filled with thousands of eternally revolving, interlocking gears, which are habitable on one or both sides. These great wheels have teeth that mesh at right angles, all turning slowly in synchronicity. Each disk has its own gravity that operates in a sphere circumscribing it exactly and pulling normal to the top and bottom surfaces. The modrons constructed it this way by using the strange anti-gravity energies that float around in the crater below. The void between the gears is filled with air, allowing easy flight. Outside a gravity sphere, objects feel only very weak attraction to nearby disks.

A city of law and order, Mechanus has equal amounts of light and dark, heat and cold, and equal measures of the four elements. There is a place for everything and everything is in its place. Even individuals living here exist to fit into the greater scheme of things and thus achieve a perfect society. Passion, fantasy, and illusion do not exist here, except for what might be brought in by visitors, and any who try to foment individualism or stir passions for a cause soon find they are not well received.