This is one of four sites which comprise the Museo Nazionale Romano (the others are the Palazzo Massimo, the Palazzo Altemps and the Baths of Diocletian). The museum is housed in several different rooms which were discovered from the Middle Ages on the site of Balbus's crypt, a portico added to the theatre built by Lucius Cornelius Balbus in 13 BC. The different levels of the museum, which include the basement crypt, house displays which explain the history of the site through archaeological finds, reconstructions, ceramics and excavations.