The Basilica of St. Clement is an extremely historical yet very well preserved basilica. It was built in the 4th century over the site of martyrdom of the Roman consul Titus Flavens Clemens, but was dedicated to Pope Clement, the third successor of St. Peter.
In the 12th century, the basilica was rebuilt on top of the old basilica. Well preserved and extremely beautiful mosaics that date back to that time can still be found. Some of the 4th century mosaics are also preserved. This basilica is one of the most colourful ones you can find in Rome. St. Clement is my personal favourite basilica in Rome.
Relics of the Apostolic Father St. Ignatius of Antioch, disciple of St. John the Apostle, are interred in the basilica. He died around 108 AD, the third bishop of Antioch. His seven letters to various communities are of tremendous historical and theological values. The saint is also my personal favourite.