Abstract: A collapsible structure useful for such applications as a portable garage, greenhouse, camping or camouflage covering comprises a pair of hub members detachably connected to one another by hub connector and a plurality of spring-steel joist members pivotally mounted in the hubs and serving to support a stretched skin thereover. The structure is held stably in either open or closed position by the combination of a Landau-type locking mechanism and a sheathed spring.