The theatre of Dionysus, one of the most important ancient Greek theatres, dominates the archaeological site of the south slope of the Acropolis. No trace has been preserved of the 5th-century theatre which must have been simple in form with a few rows of wooden and stone seats. The preserved ruins belong to the monumental theatre built by Lycourgos. The permanent skene (stage) was then constructed, extending in the width of the orchestra. The cavea once seated 17,000 spectators, was built in about 340 BC. After its destruction by Sulla in 86 B.C., the theatre and the skene were rebuilt. Extensive changes were made to the orchestra and the skene during the Hellenistic and the Roman periods.