The ancient theater is built in a natural hollow part of the hill and based on Hippocrates, it dates back to the 5th century B.C. At the beginning of the 3rd century B.C. the stage was built with a marble facade. The front part of the stage was made by Thasian Afsistratos (son of Kodi) to honor Dionysus. In ancient years, the theater was used for theatrical and musical performances. Later, in Roman times, the orchestra and the seats were renewed but in several seats you can still see the engraved names of the people who held these positions.
After the 1st century A.D, the theater was used for "hunting" and for gladiator fights. There were also fights with horsemen. The orchestra became the arena and around the middle of the 2nd century A.D, Iragoras (son of Effrilos) set up a metallic fence in order to isolate the viewers. During that period they also drew representations of gods who were famous back then: Dionysus while giving his panther of the last drops of wine, Hero Horseman and God Ares with his helmet. At the ends of the colonnade there were representations of Nemesis ordered and paid by Gladiators.