Roundhouse Cupola A plaque reads: THIS PASSENGER CAR ROUNDHOUSE WAS ERECTED 1883-1884, AND WAS USED FOR CONSTRUCTION AND REPAIR UNTIL APRIL 1953. IT WAS OPENED WITH APPROPRIATE CEREMONIES AS THE BALTIMORE AND OHIO TRANSPORTATION MUSEUM JULY 2, 1953. THE BUILDING IS 240 FEET IN DIAMETER AND 123 FEET HIGH. NOTE THE UNIQUE SUPPORT OF THE CUPOLA, SUSPENDED ON THE IRON RING, THE EXCELLENT NATURAL LIGHTING AND THE BEAUTIFUL SYMMETRY OF INTERIOR AND EXTERIOR. THE ARCHITECT WAS E.F.BALDWIN OF BALTIMORE. 9/1999