the supply tunnel of the cistern survives as well, pointing to the northeast. The sewage network of the castra must have been extensive and would have followed the slope of the hill, discharging into the main sewer running under the intervallum in Alcide De Gasperi Street. The first stretch of this main sewer - 0.9 metres wide - was discovered in 1915–6 at the intersection of Alcide De Gasperi Street and San Francesco d'Assisi Street. "Praetorium" Unfortunately, nothing can be discerned of the praetorium, the main building of the castra. All that is known is that, since it must have been found at the intersection of the via praetoria and the via principalis, it must be under a block of houses at the end of Aurelio Saffi Street. Roman Amphitheatre The Roman Amphitheatre of Albano Laziale is one of the most unusual monuments of the castra. For a long time it was believed to have been part of the Villa of Domitian, but the archaeologist Giuseppe Lugli dated it to the middle of the third century AD - well after the construction of the castra and even of the baths. The building, with a maximum length of 113 metres, could fit 14,850 seats and contain up to 16,000 people. Today, the southern half of the amphitheatre is visible, while the northern part is buried under the retaining walls of San Francesco d'Assisi St and Anfiteatro Romano Street. Among the other remains, partially carved from the living rock and partially built of opus quadratum, are the pulvinar (the Imperial box), some very unusual and "bizarre" substructural archways, and vomitoria (access corridors). With respect to the wider complex, remains have been found of a paved street which probably followed the course of the modernday Anfiteatro Romano Street to link up with the Appian Way and followed the modern "galleria di sopra" in the other direction to the Villa of Domitian. Future excavations might also clarify whether a connection with the porta decumana of the castra also existed. Baths of Caracalla The Baths of Caracalla or of Cellomaio are even today the most conspicuous evidence of the castra’s period of greatest splendour. Built by the Emperor Caracalla for the use of the legion in the period after the construction of the castra but before the construction of the amphitheatre, they later contained an entire Medieval neighbourhood. The best conserved part of the baths