Step inside the magnificent 12th-century Basilica of San Clemente, one of Rome's finest medieval churches, and admire its glittering golden apse mosaic, Cosmatesque marble floor, and beautiful frescoes. Descend into the 4th-century Early Christian basilica, one of Rome's earliest public churches, where remarkably preserved frescoes and the famous Legend of Saint Clement reveal the birth of Christian Rome. Continue deeper into the underground archaeological excavations to explore a 1st-century AD Roman neighborhood, including ancient streets, noble residences, and a natural spring that still flows today. Discover the remarkable Temple of Mithras (Mithraeum), one of the world's best-preserved sanctuaries dedicated to the mysterious Roman cult of Mithras. Travel through nearly 2,000 years of history as your expert guide uncovers the transformation of Rome from a pagan empire into the heart of Christianity.