This tour has two sections: Start your tour in the magnificent Basilica of St. Clement and venture deep underground below its foundations. Journey through several layers of history and earth down to the ancient Mithraic temple underneath and gradually uncover the structures built on top of it. Continue the visit to the basilica of Santa Maria Maggiore and admire its mosaics of the fifth century, a reliquary that is said to contain a piece of the crib that once held baby Jesus, an ancient icon of the Virgin Mary, and the tomb of St. Jerome and the tomb of the artist Gian Lorenzo Bernini.