The Claw Viper Temple is hidden deep in the Valley of Snakes beyond the Lost City. The second level, called Ritual Chamber, is the location of the Tainted Sun Altar, which is guarded by Fangskin and its pack of Salamanders. Teleport and Town Portal is disabled on this level.
The evil shrine was somehow responsible for perpetually eclipsing the sun; its destruction is required for the completion of the Tainted Sun quest and will also award the player with the Amulet of the Viper, a component of the Horadric Staff.
