COLOSSEUM, the Flavian amphitheatre in Rome, begun by Vespasian, on the site of part of Nero's famous Golden House, and inaugurated by Titus in A.D. 80. It consisted originally of three arcaded storeys of stone and an upper gallery, originally of wood, which was rebuilt of stone in the present form sometime in the third century. The colosseum probably seated between 40,000 and 50,00o people. It is elliptical in plan with its long axis 6 2of t. and its short axis 513 f t. ; its arena, 281 ft. long and 177ft. wide. Its total height to the top of the third century stone screen wall is about 16o feet. For a further description see AMPHITHEATRE.