- The Colosseum was commissioned by the Flavian dynasty (72-80 AD), not Julius Caesar.
- It was built on the site of Nero's private lake to return land to the public.
- Engineering utilized Roman concrete (volcanic ash, lime, seawater) and travertine limestone.
- The arena held 50,000-80,000 spectators for gladiator games, animal displays, and mock naval battles.
- The structure's decline was gradual, accelerated by the 1349 earthquake and its use as a stone quarry.
- It remains a global icon of engineering and social control.