The Basilica di San Clemente is one of the oldest and most impressive churches in the Eternal City. It consists of three parts: a 4th-century church underneath the basilica, the house of a member of the Roman aristocracy, and the present basilica built during the medieval period. Just a 5-minute walk from the Colosseum, this hidden gem is often overlooked by visitors. But, if you don’t visit it when in Rome, you are missing out.