The Roman structure used for chariot races was the Circus Maximus. Located in ancient Rome, it was the largest and most famous circus in the empire, capable of seating up to 250,000 spectators. The Circus Maximus featured a long, oval track surrounded by stands for spectators, and it hosted various events, primarily chariot races. These races were incredibly popular and part of Roman public life, drawing huge crowds. The facility was also used for other entertainment, including gladiatorial games and public gatherings, making it an essential aspect of Roman culture and society.