Inside the enclosure of Castro Pretorio [Praetorian Camp], along the perimeter wall, there was a continuous series of cells for the accommodation of soldiers (contubernia), dating back to the time of Tiberius. Some of these cells are preserved within the area of the “Castro Pretorio” Primary Cabin, belonging to ACEA, the water company. The barrel vaults of the small dormitories can be seen below; these rooms were covered by barrel vaults, had walls in opus reticulatum (also known as reticulate work) and black and white mosaic floors that are now 2 metres deep. In one of the cells where frescoes are preserved, a Praetorian left the graffitti written in beautiful calligraphy, “Hercules hic habitat” (Hercules lives here).
Above the barrel vaults is the walkway of the Castro Pretorio, originally bordered externally by a crenelated parapet, which was later raised in different stages.
Other well-preserved contubernia can be found inside the Castro Pretorio barracks, partly reused as storerooms and service rooms.
