Final answer:
The structure built by the Romans for sporting events was the Circus Maximus, a massive stadium used for chariot races and other public spectacles.
Step-by-step explanation:
The structure built by the Romans for sporting events was the Circus Maximus. This structure was a massive stadium used for chariot races and other public spectacles. It could hold up to 250,000 spectators and had a long rectangular shape with a track in the middle.