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 panels called "emblemata" were inserted into walls or as the highlights of larger floor-mosaics in coarser work. The normal technique, however, was "opus tessellatum", using larger tesserae, which were laid on site. There was a distinct native Italian style using black on a white background, which was no doubt cheaper than fully coloured work. A specific genre of Roman mosaic obtained the name "asaroton" (Greek "unswept floor"). It represented an optical illusion of the leftovers from a feast on the floor of rich houses. A hypocaust was an ancient Roman system of underfloor heating, used to heat houses with hot