The Basilica of St. Peter, which you'll see in the Italian language as 'Basilica di San Pietro' is situated within the Vatican City. It ranks as one of the holiest sites in the world, and while it may be the most renowned of Rome's plentitude of basilicas, cathedrals, churches and chapels, it actually is not the first-ranked, as this honor is held by the Pope's very own cathedral, the Basilica of Saint John Lateran.