The Colosseum, Roma, ITALY
The Colosseum measured 48 metres high, 188 metres long, and 156 metres wide. The wooden arena floor was 86 metres by 54 metres, and covered by sand. Its elliptical shape kept the players from retreating to a corner, and allowed the spectators to be closer to the action than a circle would allow.
The Colosseum was ingeniously designed. It has been said that most spectacle venues (stadiums, and similar) have been influenced by features of the Colosseum's structure, even well into modern times. Seating (cavea) was divided into different sections. The podium, the first level of seating, was for the Roman senators, and the emperor's private, cushioned, marble box was also located on this level. Above the podium was the maenianum primum, for the other Roman aristocrats who were not in the senate. The third level, the maenianum secundum, was divided into three sections. The lower part (the immum) was for wealthy citizens, while the upper part (the summum) was for poor citizens. A third, wooden section (the maenianum secundum in legneis) was a wooden structure at the very top of the building, added by Domitian. It was standing room only, and was for lower class women.
Underneath the arena was the hypogeum (literally, "underground"), a network of tunnels and cages where gladiators and animals were held before contests began. There were also numerous trap doors in the arena floor for the various animals hidden underneath. The arena floor no longer exists, and the hypogeum walls and corridors are clearly visible in the ruins of the building. The entire base of the Colosseum was equivalent to 6 acres (160,000 m²).
A most ingenious part of the Colosseum was its cooling system. It was roofed using a canvas covered net-like structure made of ropes, with a hole in the center. This roof sloped down towards the center to catch the wind and provide a breeze for the audience. Sailors manipulated the ropes. The Colosseum also had vomitoria — passageways that open into a tier of seats from below or behind. The vomitoria of the Colosseum in Rome were designed so that the immense venue could fill in 15 minutes, and be evacuated in 5 minutes. Each entrance and exit was numbered, as was each staircase. There were 80 entrances at ground level, 76 for ordinary spectators, two for the imperial family, and two for the gladiators. The vomitoria quickly dispersed people into their seats and upon conclusion of the event disgorged them with abruptness into the surrounding streets — giving rise, presumably, to the name.