Meet your guide at Piazza San Clemente, pay your entrance fee, and make your way inside the square’s centrepiece basilica. Your skip-the-line ticket allows you to whisk past any long lines. As you enter, listen to your guide to learn about the 3-tiered basilica, which was built over the 1st, 4th, and 12th centuries. Starting inside the 12th-century building, you’ll admire the rich ornamentation of the interior as you hear about Cardinal Anastasius for whom the church was built. Gaze at a Byzantine mosaic with an arabesque motif, and stare in wonder at the frescoed floor of the edifice. The 4th-century basilica lies one level beneath the ground. Head down to explore the aisles and central naves as your guide talks about St. Alexius and St. Clemente, whose lives are depicted in magnificent frescoes. Walk down to the basilica’s lowest level where the remains of the 1st-century building await. Discover once-secret rooms, such as a Mithraic schoolroom, and work your way around a tangle of rooms and corridors made from volcanic stone. Your next site to visit during this tour is the Santi Quattro Coronati Church: originally buit in C. IV the church owes its name to the tradition of the martyrdom of four Roman soldiers who refused to adore Esculapio. You will visit the Oratorio di San Silvestro with the decorations with frescoes dated C. XIII wich show some episodes from the legend of Costantino. The assemble of buildings still show the severe character it had during the Middle Ages, when it was used as a defensive bastion fro the nearby Basilica di San Giovanni.