Introduction to St. Peter's Basilica: St. Peter's Basilica is located in the Vatican, the "state within the city" of Rome. It was first built in 1506 and completed in 1626. It has a large dome with a diameter of 44 meters, which is magnificent in shape and extraordinary in spirit. , is the highest example of the integration of Italian architecture, sculpture, painting and other arts during the Renaissance, and is also the largest Catholic church in the world.