St. Peter’s Basilica, also known as Old Saint Peter’s, is one of five patriarchal basilicas in Rome (St. Peter’s, St. John Lateran, St. Mary Major of Santa Maria Maggiore, St. Lawrence Outside the Walls, and St. Paul’s Outside the Walls). St. Peter’s Basilica is the first Roman Catholic church, built in 330 AD,  and it is believed to have been built on top of St. Peter’s burial site. At one point (in 1546), Michelangelo was the chief architect for the basilica.