The Colosseum originally the Amphitheatrum Flavium is an elliptical amphitheatre in the centre of the city of Rome, Italy, the largest ever built in the Roman Empire, built of concrete and stone] It is considered one of the greatest works of Roman architecture and Roman engineering.
Occupying a site just east of the Roman Forum, its construction started in 72 AD under the emperor Vespasian and was completed in 80 AD under Titus, with further modifications being made during Domitian's reign (81–96).
Capable of seating 50,000 spectators, the Colosseum was used for gladiatorial contests and public spectacles such as mock sea battles, animal hunts, executions, re-enactments of famous battles, and dramas based on Classical mythology. The building ceased to be used for entertainment in the early medieval era. It was later reused for such purposes as housing, workshops, quarters for a religious order, a fortress, a quarry, and a Christian shrine.