Paraelemental Plane of Ooze
From Ardrana
The Paraelemental Plane of Ooze is all mud and slime, a quivering ocher ocean of muck - hardly the place a cutter cares to go. It's a place of torturous death and exile, too. With a wave of the hand, evil wizard-tyrants send their enemies here to drown, choking on lungfuls of stagnant silt. Kinder souls merely imprison their foes here, sealing them inside bubbles of pure air. Oh, sometimes they forget the other niceties of food and water, leaving their prisoners to slow starvation, but at least they kept them from immediate death. Even those fully provided for face unhappy fates, for there's little or nothing to stave off the madness that boredom brings. Small wonder the plane is also known as the House of Chambered Madness.
Little relieves the unending ocean of muck. Toward the Elemental Plane of Earth, the mud grows drier, filled with abrasive grit, and toward Water it thins into rippling silt that a cutter can easily swim through. Drifting through it all are blocks of stone and puddles of clear water. All in all, it ain't a popular rest stop.
Note: The Paraelemental Plane of Ooze originally appeared in this form in the Planescape AD&D campaign setting from TSR. Its use here is for the purposes of providing context for the campaign only.