Although almost two-thirds of the Colosseum has been destroyed, over time, it is still a magnificent sight to behold. Ravaged by weather, time, and human interference you can still make out the underground tunnels that housed animals and the gladiators, and what it would have been like to sit in the stands. At its peak use, it would have held around 50,000 spectators on four different levels. Of course, level one was reserved for the elite, and the general public would use the higher levels. It even had special boxed seating areas for the Emperor and his guests. A velarium would have been pulled tight across the top opening of the Colosseum, to protect the spectators from sun and rain. The hypogeum, two levels of underground tunnels, not only held the animals and gladiators, but included trap doors that were operated by a lift and pulley system. The colosseum floor could even be flooded, and boats would reenact sea battles. It was used for gladiator fights, for almost two hundred years, before it fell out of favor. This was mainly due to the spread of Christianity, to the region. The arena was then used for animal hunts and shows. Exotic animals from all over the world were brought to Rome, for these hunts. Some of the wild animals included leopards, lions, bears, hippopotami, elephants, and crocodiles.
Now it is just a shell of what it once was, but it is definitely worth a visit inside. I would also recommend purchasing the audio tour. It is filled with fascinating information not only on the architecture, but on some of the events that took place. And if you have the opportunity, they offer a tour where you can visit the third level and underground! The next time I am in Rome, I may just have to splurge on that tour!