Possibly unique on Athas, the so-called Lost Oasis features a natural geyser, located in the middle of a salt flat, that periodically shoots scalding water to the surface. Despite its high mineral content, the steaming water nourishes a grove of trees. The oasis is located near Fort Melidor and the ruins of Kalidnay.

The Oasis has one semi-permanent inhabitant, an addled old man calling himself Lionus. Another individual by the name of Durwadala occasionally is seen at the Oasis.