The Circo Massimo (greatest circus) is an ancient Roman chariot racing stadium and now a public park and mass entertainment venue situated in the valley between the Aventine and Palatine hills. It was the first and largest stadium in ancient Rome (621 x 118 m) and could accommodate over 250,000 spectators.
Its obelisk, brought by August from Egipt, is now in Piazza del Popolo.