Built in 8 BC as attested by the inscriptions found on its grandstand, the Amphitheatre served as the setting for very popular shows: the games of gladiators, hunts of wild beasts, and the struggle between wild animals in artificial settings recreating forests, jungles with lakes, or deserts – all atop the large wooden platform that was known as the arena. The approximate maximum capacity of this giant ring was between fifteen and sixteen thousand spectators.

Adjacent to the Theatre, the Amphitheatre is separated therefrom by a road that surrounds both buildings. This building was raised in a similar way to the Theatre and, likewise, it is the result of various phases. To reduce costs, part of the grandstand stood on stone boxes filled with tightly-rammed earth. The facing of the walls was of local stone that had been smoothed down. Sometimes the layers of the walls' facing were evened out with a row of bricks. For the arches of the access openings, ashlar masonry was used featuring the characteristic bossage of the Augustinian period.

The distribution of the stands was similar to that of the Theatre, although today only the ima cavea and some sectors of the media cavea are well preserved. In three of the axes of the ellipse, you can note the existence of four monumental doors that led into the arena from the outside through wide corridors, two of which were tiered.

In different sections of each corridor doors existed that, by means of stairs, gave access to the stands. The judges' stand was located above the door of the western axis, although it is not preserved today. In front of said judge's stand, on the eastern axis, was the stand from which those who had sponsored the show looked on. This stand remains today, partially restored. The sponsors accessed the arena through a few small stairs.

The grandstand was separated from the arena by means of a granite platform that was clad with slabs of marble, as demonstrated by the presence of the anchor holes in the platform's ashlar masonry. Atop this, there was a barrier made with granite ashlar. On the side facing the grandstand, this ashlar had paintings alluding to the gladiatorial games and the contexts in which they developed.

Flanking the doors of the main axes, there are a number of rooms that were either used as cages for the wild beasts or as rooms where the gladiators got ready.

The presence of a large pit can be seen in the arena. There, the wooden pillars that held up the performance platform were secured. Under said platform, all the inventions necessary for the undertaking of such complex shows were installed, hidden.