Built by Vespasian and completed by Titus in 80 AD, the Roman Colosseum (also Roman Coliseum) is considered by many to be the symbol of Rome. While only the skeleton of this Flavius amphitheater remains it was once the biggest and most imposing in the Roman world. As you tour this elliptical arena imagine what it looked like long ago. The first three floors had 80 arches each. The arches on the second and third floors were decorated with enormous statues. The Roman Colosseum was once completely covered in travertine stone slab and seated more than 50,000 people. And to celebrate the opening Titus held a ceremony that lasted 100 days. The performances included gladiator games and hunts some of which included thousands of animals. For the naumachia the Colosseum was filled with water and real naval battles were held. So what happened to all the missing pieces? The Popes who ruled Rome in the Middle Ages used the Colosseum as a quarry. They removed the marble, iron and lead and used it to build edifices around the city.