Flavian Amphitheater July 10 Known simply as 'the Colosseum', the immense structure of the Flavian Amphitheater was dedicated for use in 80 A.D. Engineered to hold some 50,000 spectators, the ellipse shaped Colosseum featured an elaborate network of subterranean chambers and machinery designed to stage spectacular battles among gladiators and wild beasts. A dominating presence even by today's standards, the Colosseum integrated all the principal Roman orders in the exterior facade: Tuscan, Ionic, and Corinthian for the three main levels, with tall Corinthian pilasters at the uppermost attic area.