The work on this theatre began in Caesar's time and was completed under Augustus. It could accomodate 15,000 spectators. In the 16 th century, it became the palace of the noble Savelli family. The stage and terraces have gone, but you can still see a double row of harmonious-looking, superposed arcatures. The third arcature disappeared when Baldassare Peruzzi built a house there, during the palace's construction. The whole structure resembles the Colisseum.