Salem's Domain is best described as a barren wasteland, with rocky terrain and enormous purple crystals sprouting from the ground. The sky is stained a dark red. Grimm spawn in large numbers from pools of a viscous, tar-like substance.
The realm is first glimpsed in "End of the Beginning". In "The Next Step", Salem meets with her subordinates in a large meeting room, hinting that there is some sort of building at the location. However, the building's exterior is not shown.
In "Taking Control", Cinder trains her Fall Maiden powers against various kinds of Grimm in a large circular room with a skylight in the dome.