The Rim is the uppermost layer of Sunhallow, a rocky expanse of cliffs, winding tunnels, and cavernous drops.

Though dangerous, it is the most well-mapped and frequented layer, primarily used as an entry point for divers to descend. The terrain is treacherous, yet it provides the most reliable route to lower levels, and even beginner divers can return with scraps and trinkets worth a small fortune.