Side Theater is at the narrowest point of the peninsula and where the city center is located. The part of the cavea (rows of seats) up to the diazoma (the road in the middle of the steps) is leaning on a slope, while the upper part is seated on vaults. With this feature, the theater is one of the unique examples in Anatolia. The stage building has three floors. The characteristics of the Antonine Period are seen in its ornaments. There is the Dionysus Frieze on the podium of the first floor. In the frieze, the life of Dionysos, the god of wine and the ruler of the theater, is described chronologically from west to east. In the theater dating back to the 2nd century AD, the orchestra must have been surrounded by a high wall in the 3rd century AD and transformed into an arena. It is known that chapels were built inside the theater in the 5th century AD and the theater was used as a sacred place (open air church) in the Early Christian Period. The theater has maintained its feature of being a sacred space until the last period it was used.