The Plutonic Realms is the catch-all term for the great caverns and tunnels that run deep in the roots of Aquerra's islands. They once were connected by the legendary tunnels of the Undersea, but since most of those tunnels had already been destroyed by the dawn of the Third Age, the various pockets of the Plutonic Realms have been isolated for over two millennia.

The largest and deepest portions of the Plutonic Realms are said to house cities of subterranean creatures. Most entrances to the Plutonic Realms are found in Derome-Delem, but any mountainous region could reasonably have one. These entrances into the "true" and deep Plutonic Realms are usually deep underground; when they are found by races that dwell near the surface, such as dwarves and gnomes, they are either sealed or carefully warded.

See also: Drow, Geography, Undersea