I know that many people will say to stay well away, but I would disagree with them completely. We visited early in the morning, didn't have any tickets pre-bought and were prepared for lines. Fortunately though they were short and we weren't kept waiting long. Inside the Colosseum itself, there isn't a great deal as far as information. But it is such a spectacular sight. A guided tour might have enhanced it a bit but I don't think it was entirely necessary.