The Roman Colosseum
The major axis of the Roman Colosseum's elliptical plan is 188m long, the minor axis attains 156m, and the walls in the outer ring rise to almost 50m above ground. More than 100,000 cubic meters of travertine were used to build it and even the metal pins that held the blocks together must have weighed more than 300 tons. The ceremonies and games on occasion went for a hundred days and some 5000 wild animals were put to death during that time. The eighty arches at ground level were progressively numbered and led, via a system of internal corridors to the 160 outlets that took the visitor to his place on the steps of the cavea, which was borne up by arches and vaults. A complex system of passages and rooms extended beneath the arena: it was probably constructed under Domitian, after it had been decided that no further 'naval battles' would be staged there. These underground rooms contained facilities and stored the stage equipment for the shows.