during the great earthquake in 1349, the outer south side fell down. most of the fallen stones were used to build palaces, churches, hospitals and other buildings in rome. in the middle of the 1300s, a religious group moved into the north part, and were still there in the 1800s. the inside of the colosseum was used to supply building stones. the marble facade was burned to make quicklime. the bronze clamps which held the stonework together were ripped off the walls leaving marks that can still be seen today.