Gehenna

Gehenna is the plane of suspicion and greed. It is the birthplace of the yugoloths, which dwell here in great numbers. A volcanic mountain dominates each of the four layers of Gehenna, and lesser volcanic earthbergs drift in the air and smash into the greater mountains.
The rocky slopes of the plane make movement here difficult and dangerous. The ground inclines at least 45 degrees almost everywhere. In places, steep cliffs and deep canyons present more challenging obstacles. Hazards include volcanic fissures that vent noxious fumes or searing flames.
Gehenna has no room for mercy or compassion. The fiends living here are among the greediest and most selfish in all the multiverse.

Optional Rule: Cruel Hindrance

The plane’s cruel nature makes it difficult for visitors to help one another. Whenever a visitor casts a spell with a beneficial effect, including a spell that restores hit points or removes a condition, the caster must first make a DC 10 Charisma saving throw. On a failed save, the spell fails, the spell slot is expended, and the action is wasted.

Type

Dimensional plane