The San Saba district in Rome (R. XXI) is also called Piccolo Aventino (small Aventine). The name San Saba is inherited from the main church in the rione with its adjacent convent. The first inhabitants of the area after the fall of the Roman Empire were the people living in this convent.
San Saba District Rome (Rione XXI)

The convent dates back to the 8th century AD. Before that there was a number of hermits who had taken up abode in a former barracks, on a hill between the present Porta San Paolo and the Porta San Sebastiano.
In the beginning of the 20th century, part of San Saba, until then more country-side than city, was designated to become an area of houses for the middle class.
The present heart of San Saba is formed by the gardens of Piazza Bernini, where the area’s public life unfolds. The district is exteremely livable, since the presence of the Terme di Caracalla prohibits the building of new constructions.
Apart from the aforementioned Terme di Caracalla and San Saba Church the main tourist attraction of the area is the Porta San Sebastiano. The Santi Nereo e Achilleo Basilica near the Baths contains some frescoes by Pomarancio, but is hardly ever open.
The rione San Saba is situated more or less east of of an imaginary line one could draw between the metro stations of Circo Massimo and Piramide.