Photo by Elizabeth Lyding Will

The Circus of Maxentius, built outside ancient Rome’s walls in 309 B.C., is a 1,690-foot-long oval designed for chariot races and other sports. This detail showing the circus’s wall illustrates a secondary use of amphoras—as building material (compare with full view of wall at Circus of Maxentius). Whole amphoras were mortared into the lower part of the ceiling that jutted out over the spectators’ benches. Amphoras have also been found built into speakers’ platforms to enhance acoustics, as well as in walls, foundations and breakwaters.