The amphitheatre is the most important monument of the former Roman colony that we should admire, some two thousand years after its construction. Its architecture is entirely designed in relation to its vocation of place to great shows, hosting a large audience. In their initial rise, the bleachers could receive approximately 21 000 viewers, streams were cleverly organised by a network of doors, galleries and stairs, on several floors.Become at the beginning of the middle ages a city close and fortified, the building was cleared only in XIX century. He himself then for part, its original function, including bullfighting, which earned him his current common appellation of "arenas".It is today the monument of the most visited city, bringing the image of Arles in the world.With a major axis of 136 metres in length and a minor axis of 107 metres, the amphitheatre of Arles is slightly larger than that of Nîmes and the 20th ranked among those of the Roman world. It has a shape of an ellipse. The façade includes two levels of sixty semicircular arches, separated by the abutments, massive rectangular section. A wider opening points out the ends of the two axes of the monument. The main entrance was not North as today, but the West where we can see the remains of a staircase overlooking the city.The cavea, space reserved for spectators, included 34 stands, divided into four series: the maeniana, where viewers were divided according to their social status. It is estimated the initial capacity of the monument to some 21,000 people.