Ancient Roman architecture 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. 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
Ancient Roman architecture of these developments are described by Vitruvius, writing in the first century AD in his work De Architectura. Although concrete had been used on a minor scale in Mesopotamia, Roman architects perfected Roman concrete and used it in buildings where it could stand on its own and support a great deal of weight. The first use of concrete by the Romans was in the town of Cosa sometime after 273 BC. Ancient Roman concrete was a mixture of lime mortar, aggregate, pozzolana, water, and stones, and was stronger than previously-used concretes. The ancient builders placed these ingredients in wooden frames