The theater of Side is obviously one of the most important theatres in Anatolia. This was one of the largest structures of its time in Asia-Minor. It was built during the 2nd century A.D. with a Roman technique, rather than a Hellenistic one. The most important feature of this technique was to build the theatre on a flat land, not on a hill side, like most of the other Anatolian theatres. This theater is a great exception to Anatolian building tradition. It uses a vaulted construction to support the tiers.
It is a semi-circular structure with 49 tiers, divided with a gallery in the middle. Approximately, 15,000 spectators could be seated. The upper section of the theater was covered with a gallery, supported by arches.
The 63 m. long and 9 m. wide stage has ruined to a large extend over the centuries. There are three entries to the orhestral area from the stage.
During the Roman age the theater was used as an arena for gladiator and wild animal fights.