Malbolge
Malbolge comprises one infinitely large, steep-sloped mountain. Boulders and other debris rain down from its heights in frequent avalanches. Some of the structures here are erected atop pillars of adamantine embedded in the mountain that can withstand the constant battering, though the platforms they support sway under the force of the onslaught. Condemned devils are typically trapped in cages, which are lowered on chains to hang beneath the platforms. From such a vantage, the prisoners are continually battered by Malbolge’s avalanches, causing injuries that are agonizing but never fatal.
Some locations on the mountain are shielded from the rockfall by structures that have projections pointing upslope so that avalanches wash around the protected areas beneath. Roofed trenches and tunnels make travel between locations possible, if perilous.