One of the main reasons why Roman Colosseum is broken and partly destroyed is because after the fall of Rome most of the existing structures were used as materials for the creation of new constructions. Moreover, in the 7th century there was an earthquake in Rome, which destroyed part of the Colosseum. After the fall of the Roman Empire, the amphitheater was robbed by people, so many materials and decorative marble structures as statues have disappeared.
The Colosseum exists for almost 2000 years
Its construction began in 72 AD by Vespasian and finished in 79 AD by his son Titus. In 80 AD, the Colosseum was officially opened and there were 100 days of the celebration of its opening. This is the grandest ancient amphitheater in the world. Despite the fact that it went through several damages and many materials of the structure were stolen, the Colosseum remains one of the wonders of the world and you can still visit this ancient amphitheater in Rome nowadays.