<P> The oldest known basilica, the Basilica Porcia, was built in Rome in 184 BC by Cato the Elder during the time he was Censor . Other early examples include the basilica at Pompeii (late 2nd century BC). After Christianity became the official religion, the basilica shape was found appropriate for the first large public churches, with the attraction of avoiding reminiscences of the Greco - Roman temple form . </P> <P> The Roman circus was a large open - air venue used for public events in the ancient Roman Empire . The circuses were similar to the ancient Greek hippodromes, although circuses served varying purposes and differed in design and construction . Along with theatres and amphitheatres, Circuses were one of the main entertainment sites of the time . Circuses were venues for chariot races, horse races, and performances that commemorated important events of the empire were performed there . For events that involved re-enactments of naval battles, the circus was flooded with water . </P> <P> The performance space of the Roman circus was normally, despite its name, an oblong rectangle of two linear sections of race track, separated by a median strip running along the length of about two thirds the track, joined at one end with a semicircular section and at the other end with an undivided section of track closed (in most cases) by a distinctive starting gate known as the carceres, thereby creating a circuit for the races . </P> <P> A forum was a central public open space in a Roman municipium, or any civitas, primarily used as a marketplace, along with the buildings used for shops and the stoas used for open stalls . Other large public buildings were often sited at the edges or close by . Many forums were constructed at remote locations along a road by the magistrate responsible for the road, in which case the forum was the only settlement at the site and had its own name, such as Forum Popili or Forum Livi . </P>

The most important roman architectural feature was the arch