Amphitheater of Tarraco, at Tarragona.
Built at the end of 1st century or beginning of 2nd one, it was placed out of the walls, at one side of Augustus Way, close to the Circus and the Provincial Comitium. It is a good instance of one of the most important Imperial wholes form Roman world.
As other amphitheaters, a part of its rows were supporte by a mountain side in order to use its slope for leaning rows. A section of them is directly excavated on the rock. Opposite side is supported by archs and concrete vaults -opus caementicium-, making a typicall hollow structure.
Its capacity was for 15.000 spectators. It was 110 m. long and 86 m. wide. Arena -being 60 m. x 38 m.- was separated from the rows by a podium that elevated it. Podium was covered by marble.
It was endowed with a fossa bestiaria, used then for constructing two Christian buildings: a Visigothic and a Romanic. Origin for them is martyrdom of Bishop Fructuoso and Deacons Augurio and Eulogio, at year 257 during Decio's persecucions. Later, many burials were made around it.
Its exterior façade was composed by a series of archs.