The Colosseum in Rome impressed the world when completed in 80AD, continued to impress throughout the Middle Ages and Renaissance, and still does so today. If it is still Rome's greatest landmark, an unfailing magnet for tourists, it is also a brilliant example of Roman technology at its most sophisticated, a smooth-running machine in stone, cement and marble that for centuries staged Rome's lavish if brutal entertainments. This book investigates its construction, its workings and history, including its recent triumphant restoration.