In Elden Ring, the underground region containing the Worshippers’ Woods is Siofra River. This vast subterranean area is reached through wells on the surface, including the Siofra River Well in eastern Limgrave.
Siofra River combines underground ruins, ancestral spirits, elevated cliffs, and a star-filled artificial sky. The Worshippers’ Woods is one of its notable areas and contains the large deer-like Ancestor Spirit boss arena. Progress through the region also connects to events involving Blaidd and the search for Nokron.
Siofra River is often confused with Ainsel River, another underground zone with its own well, ruins, and quest connections. Deeproot Depths and the Lake of Rot are separate subterranean regions reached later or through different routes.