The Circus Maxentius, which is situated on the Via Appia, was built during the reign of the emperor Maxentius (r. 306-312).
The track, which is 503 metres long and between 75 metres and 79 metres wide, is one of the largest known.
The spina, the barrier running down the middle of the track, is exactly 1,000 Roman feet (296 m) long, and would have been cased in marble. The obelisk that is part of the Fountain of the Four Rivers, in Piazza Navona, once stood on the spina.