The temple, sometimes called the "Great Temple", was built during the last thirty years of the fifth century BC on the top of a hill west of the city, outside its walls. It is a large hexastyle peripteral temple. On the long side it has instead fourteen columns 10 meters high. The current state of preservation presents the entire colonnade of the complete peristasis of the entire entablature. Despite the construction elements and the proportions of the construction, they clearly refer to the period classic of Greek architecture, the temple presents peculiar aspects on which historiography does not express unanimous opinions.

​

The theater was built at the end of the 3rd century. B.C. according to the dictates of Greek-Hellenistic architecture, with blocks of local limestone. It differs from the typical structure of Greek theaters because the auditorium does not rest directly on the rock but has been purpose built and is supported by retaining walls. It consists of two entrances, slightly offset with respect to the main axis of the building and is able to hold around 5000 people. Every summer, it is possible to relive the ancient magic of the theater of Segesta thanks to the representations that are performed there. On the stage, established and emerging actors alternate, classical and modern performances, ancient dramas, dance performances, opera, operettas and musicals interspersed with performances of various kinds.