To the north-western part of the town is the amphitheatre. It is presumed to bean elliptic amphitheatre built in the 2nd century A.D. which had room for 18,000 spectators. The eastern part was the entrance for the gladiators and their assistants, whilst behind the wire-netting the animals were found. The amphitheatre also has an underground passage for bringing out injured and dead gladiators. There is also a Christian oratorio here dedicated to St. Asterio and other martyrs executed in the amphitheatre for declaring the Christian religion.