The Roman Forum
Roman Forum (ancient town center and location of the senate and other important political/ business building). Paul would certainly have walked these streets while in Rome as would Peter. Next to the forum is Palatine Hill with remains of palaces and palatial homes for the ancient rich and famous.
The Forum also contains a triumphal arch to Constantine and his victory at the battle of the Milvian bridge approx 321 AD. Constantine claimed to see a sign of the cross before the battle in the sky and he converted to Christianity and thus changed the history of the world.