Just thought i'd show a picture of my work in progress Colosseum for those interested.
It is close yet far away from completion.
I still have more detail under the seating area to finish off, I have the Hypogeum (underground) area to research and complete (might take a while getting research and materials for the underground area), I have the emperors box to finish, then the 2 main entry gates and a bunch of other details to complete such as the gallery area right up the very top of the colosseum where the screenshot was taken.