In the southern Campus Martius the complex of the Crypta Balbi extends for about a hectare, in the area that includes the churches of S. Stanislao dei Polacchi and Sta. Caterina dei Funari. The complex consisted of a piazza with a double portico on three sides, annexed to the scaenae frons of the theatre built by Lucius Cornelius Balbus in 13 B.C. On its east side was found a nucleus of insulae reproduced on the marble Forma Urbis and still within the city block on which the site is located. On the east side of the portico was a monumental exedra transformed into a latrine during the Hadrianic rebuilding of the complex. This has now been excavated and may be visited. The excavations shed light on all the successive phases of occupation of this area of the city. After antiquity life continued in the area, with transformations and reuse of the monument, which was eventually occupied by the gardens of the monastery of Sta. Caterina. It gives an extraordinary testimony to the way in which Rome developed over the century within the confines of its own ruins. The Museum of Medieval Rome is laid out within the medieval and renaissance buildings which occupie the earlier porticoed building. Its opening concludes the first phase of the project of restoration and presentation of the entire insula, a project articulated as a functional sequence of excavation, restoration and presentation. The museum guides the visitor through the most significant phases of the monument, and allows access to the portico as well as to the adjacent porticus Minucia. (Laura Vendittelli)