A lake or lake-sea associated with the Carcosa Mythos. With Alar standing upon its shore, it may be a parallel or mirror-image, in some sense, of Lake Hali with Carcosa upon its shore.
In DJ Tyrer's poem Pioneer Approaches Aldebaran, Carcosa stands upon the shore of Demhe on a world orbiting Aldebaran.
According to the Encyclopedia Cthulhiana[]
Lake whose "cloudy depths" are mentioned in references to Hastur and the King in Yellow. The city of Alar may stand on its store.
See also – Lake Hali