Probably the most-overlooked museo nazionale Romano, this museum is well known for remains of the Theater of Balbus (13 B.C.), the ruins and also the modern museum located above.

The Crypta Balbi is built around the ruins of medieval and Renaissance structures, themselves set atop the ancient Teatro di Balbus (13 BC).

Duck down into the underground excavations, then examine artefacts taken from the Crypta, as well as items found in the forums and on the Oppio and Celian Hills.