The Theatre of Marcellus (on the left) is the best preserved of several ancient open-air theaters in Rome. The grounds contain the Temple of Apollo Sosianus. The theater was built in the final years of the Roman Republic. When Rome became the capital of Italy the vast project to restore the monuments of Ancient Rome to the city also involved the Theatre of Marcellus: the theatre's arches and surrounding areas were expropriated and get rid of shops and houses, and the architecture was recovered.