At the intersection of Via Casilina and Viale Castrense is the most unique tower in the entire area, clad between the 12th and 13th centuries with rows of bricks, blocks of tuff, Peperino rock and flint, as well as fragments of marble and travertine, some of which had been carved for sarcophagi and decorated slabs. In a document from 966, the tower is referred to as turris castellum, perhaps referring to the fact that it functioned as a distribution castle for the aqueduct at this time. In 1720, it was described as a large tower and ancient castle for the water supply. In the mid-19th century, a small building with a chimney was added and used as a tavern. Ultimately, during the Second World War, the interior was used as an air raid shelter.
