Circus Maximus in Rome, north-west end of the central dividing barrier

The Circus Maximus (Latin for greatest or largest circus, in Italian Circo Massimo) is an ancient Roman chariot racing stadium and mass entertainment venue located in Rome, Italy. Situated in the valley between the Aventine and Palatine hills, it was the first and largest stadium in ancient Rome and its later Empire. It measured 621 m in length and 118 m in width, and could accommodate over 150,000 spectators. In its fully developed form, it became the model for circuses throughout the Roman Empire. The site is now a public park.
The Circus was Rome's largest venue for ludi, public games connected to Roman religious festivals. Ludi were sponsored by leading Romans or the Roman state for the benefit of the Roman people (populus Romanus) and gods. Most were held annually or at annual intervals on the Roman calendar. Others might be given to fulfill a religious vow, such as the games in celebration of a triumph. The earliest known triumph ludi at the Circus were vowed by Tarquin the Proud to Jupiter in the late Regal era for his victory over Pometia.
With the advent of Christianity as the official religion of the Empire, ludi gradually fell out of favour. The last known beast-hunt at the Circus Maximus took place in 523, and the last known races there were held by Totila, the penultimate King of the Ostrogoths, in 549.

More on https://en.wikipedia.org/wiki/Circus_Maximus