Travertine limestone, tuff or tufo, cement, tiles, bricks, marble, lead and terra-cotta pipes.
There are three main reasons why the Colosseum is broken; Firstly, it was built very long ago so, from a historical point of view, there is natural wear and tear. The natural elements for the last 2,000 years have damaged it. We cant underestimate this point.. Secondly, there were other natural disasters such as lighting strikes and earthquakes. Lastly, because the Roman Empire fell and people were building new projects, often times people used ancient sites as quarries. Also defence fortification around the Tiber were also built from the remains of the Colosseum.
Construction of the Colosseum was begun in 70 and 72 CE. It is located just east of the Palatine Hill, on the grounds of what was Nero's Golden House. The artificial lake that was the centrepiece of that palace complex was drained, and the Colosseum was built there. Vespasian, whose path to the throne had relatively humble beginnings, chose to replace the tyrannical emperor's private lake with a public amphitheatre that could host tens of thousands of Romans.
The original name of the colosseum was the Amphitheatrum Flavium or Flavian Amphitheatre. The origin was commissioned and built by emperors of the Flavian Dynasty. The Colosseum is the biggest Roman anphitheatre in the world, the name comes from a statue that once stood nearby "The Colossus Nero". The Colossus of Nero was an enormous 30m tall bronze statue, and was oine of the seven wonders of the ancient world. "As long as collosus stands, so shall Rome; when the Collosus falls, Rome shall fall; when Rome falls, so falls the world." Is often misquoted to refer to the Colosseum. in reality he is talking about the Collosus of Nero. The Collosus of nero did fall.