Mechanus/Nirvana

Mechanus, sometimes called Nirvana, is an outer plane associated with law and neutrality. This plane is filled with an infinite number of country-sized circular interlocking gears which are habitable on one or both sides. These great flat wheels are at least 1,000 miles (1,600 kilometers) in diameter and 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 the void between the gears is filled with air, allowing easy flight. Each disk has varying surface biomes, with some being not but endless forges and foundries, others holding deep mines of ore and gems, or even large forests to be harvested for carpentry. A plane of Law and order, Nirvana 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.
The plane is where the Meladrin Darsith makes his home, and his great hall of Galekgak containing space for every form of crafting invented located on one the gears. Other than the demigods that serve Darsith, the only creatures native to Nirvana are the modrons, a race of beings created by Darsith and organized in a rigid caste system, ruled by Primus, the One and the Prime.
Mechanus is connected to the Prime Material Planes via the Astral Plane, and to the Outer Planes of Arcadia, Acheron, and Concordant Opposition by portals which appear once every revolution of the gears they belonged to. The period of rotation depended on the size of the gear, but a typical period is twenty days. The portals stay open for exactly one day. There is one portal to Concordant Opposition, located at the center of the featureless bottom side of a large gear, that is continually open.

Mechanus information taken from various Wizards of the Coast sources.  Cover image credit Unknown

Type

Plane of Existence