I tried taking two photos of the area and put the together I overlapped some but you get the idea
Coliseum the holes are where they chipped the exterior away to use for other buildings mostly in St Peter's square
this was the floor those ruins were put in 10 years after it was originally built before then it was hallow and could be filled with water to reenact ship battles.
a view from the top of the Forum
This was called "The Arena" not sure what it was used for.
one of the buildings from the forum