A visit to the Pio Clementino Museum begins in the Square Vestibule. This was once the entrance to the Museum of Pope Clement XIV (1769-1774), as can be seen from the Latin inscription Museum Clementinum above the entrance arch. In the Square Vestibule today one can see the monumental sarcophagus of Lucius Cornelius Scipio Barbatus (consul in 290 B.C.) and several inscriptions found in the tomb of the noble Roman family Scipiones along the via Appia.
Passing through the Round Vestibule, one reaches the Cabinet of Apoxyomenos which takes its name from the marble statue which is a copy of an original bronze by Lisippo. Today the Cabinet is home to several inscriptions and a portrait in tuff of a young man with a crown of laurel, the so-called Ennio, which was also found in the Tomb of the Scipios.