Below Scarwall's worked stone lies a very different environment. The caverns replace straight corridors with irregular rock walls, sharp angles and a broad central space whose unusual geometry makes the route difficult to read at a glance. Natural stone closes in around the floor, while constructed edges and passages remind explorers that these caves remain part of the fortress complex.

The irregular shape is the main tactical feature. Sightlines break abruptly, corners hide movement and the central chamber can be approached from several directions. A GM can use the area for ambushes, subterranean guardians or a discovery that feels physically removed from the castle above without requiring a separate location. In Skeletons of Scarwall, these caverns give the dungeon an important change of texture and make the fortress feel rooted in something deeper than its visible walls.