The Cavern of Lost Dreams is the original city of the Doozers, as seen in the third season Fraggle Rock episode of the same name. The city is fabled amongst the current Doozers for its magnificent architecture.
The Cavern is composed of a network of firm, brick-like columns, arches, and walls, in contrast to the more streamlined, modernist Doozer towers. The towers are also much less edible than the average Doozer stick, made from old mushrooms rather than radishes. The city was abandoned when the original Doozers ran out of mushrooms and went in search of new building materials. The city was believed to be lost forever, or possibly even a myth, until Gobo Fraggle and Cotterpin Doozer rediscovered it. Yeaster Doozer and Crusty Doozer are the sole remaining inhabitants.