The ancient Roman structure primarily used for gladiatorial contests is the Colosseum, also known as the Flavian Amphitheatre. Completed in AD 80 under Emperor Titus, it is one of the most iconic and enduring symbols of ancient Rome. The Colosseum could hold up to 80,000 spectators, accommodating various public spectacles, including gladiatorial games, animal hunts, and dramatic performances. Its architectural innovations, such as the use of arches and concrete, allowed for its grand scale and complex design. The Colosseum remains a significant historical site, representing both the cultural heritage and societal values of Roman civilization.