Abstract: A prefabricated observatory dome structure comprising a base portion constructed from connectable arcuate panels, a rotatable dome constructed from connectable panels and a vertically slidable shutter. The flange design of the base portion provides a water-tight non-caulked wall. A semi-door permits easy access to the observatory structure. The shutter has three sections that slide together using a latching system to slide back to expose more that half of the opening to permit observation at the zenith of the unit.