The Doozer Dome, first seen in the second season Fraggle Rock episode "All Work and All Play," is the home of the Doozers. It is a large crystalline dome occupying an arched cavern and essentially separated from the open areas of Fraggle Rock, where the worlds of Fraggles and Doozers more publicly intersect.
The Doozer Dome encompasses the Doozer city, dotted with mushrooms, benches, and mechanized fountains, and such areas as the architect's drawing room and the Court of the Doozers. Befitting such hardworking beings as the Doozers, the Doozer Dome is filled to the brim with elevators, escalators, ramps, moving sidewalks, and various Doozer constructions. Working doozers motor to and fro on their vehicles, while mother doozers often take their children on strolls. As described by Jerry Juhl in script notes, the prismatic ceiling of the Doozer Dome changes colors in a continual rotation, and thus becomes the means by which the Doozers calculate time.
Given both the scale of the city and the general hesitance of most Doozers to interact with other species, it is rare for any outsiders to enter the Dome. Exceptions have included Large Marvin and Feenie Fraggle in "The Trial of Cotterpin Doozer," brought as witnesses (Marvin's behind clogged the doorway), and Gunge and Philo in "Gunge the Great and Glorious."
A maquette of the set is in the Canadian Museum of Civilization.