Colosseum consists of stone and concrete. It was constructed by tens of thousands of Jewish slaves under the rule of Emperor Vespasian.
189 metres long, 156 metres wide and 50 metres in height, the Colosseum is the largest amphitheater in the world.
The arena had 36 trap doors for special effects.
In Colosseum many underground passages and rooms was built to hold wild animals and gladiators before the games began.
The arena itself was 83 meters by 48 meters and It comprised a wooden floor covered by sand.
The outer wall is estimated to have required over 100,000 cubic metres of travertine stone which were set without mortar.
Travertine stone were held together by 300 tons of iron clamps.
The effects of pollution and general deterioration over time prompted a major restoration programme carried out between 1993 and 2000, at a cost of $19.3m
It was capable of holding 50,000 audience, who watched a variety of events.