Circus of Maxentius

The Circus of Maxentius is an ancient structure in Rome, Italy, part of a complex of buildings erected by emperor Maxentius on the Via Appia between AD 306 and 312. It is situated between the second and third miles of the Via Appia, between the basilica and catacombs of San Sebastiano and the imposing late republican tomb of Caecilia Metella, which dominates the hill that rises immediately to the east of the complex. It is part of the Appian Way Regional Park.

Source: Wikipedia