The Circus of Maxentius (also known as the Circus of Caracalla) is an ancient Roman circus built as part of a funerary complex by the emperor Maxentius.
The Circus of Maxentius was built of bricks and sod at the beginning of the fourth century near the Via Appia. It is the best preserved of all Roman circuses. It was 513 meters long and 91 meters wide, and held some 10,000 people. It was part of an imperial villa that was (probably) never used.
The obelisk of the circus is now at the Piazza Navona, Rome. It is not a real Egyptian obelisk: it was made in 81 AD and erected as a monument to the emperor Domitian and may have been at the temple of Isis. Later, it was brought to the Circus of Maxentius, and in the seventeenth century returned to a place near its old site, where it now adorns Bernini's famous Fontana dei Quattro Fiumi.