St. Peter's Basilica is an Italian Renaissance church in Vatican City, the papal territory within the city of Rome.  It's built in the Renaissance style located in the Vatican City west of the River Tiber and near the Janiculum Hill and Hadrian's Mausoleum. Its central dome dominates the skyline of Rome and rises to a total height of 448.1 ft from the floor of the basilica to the top of the external cross. It is the tallest dome in the world. The basilica is approached via St. Peter's Square, a forecourt in two sections, both surrounded by tall colonnades. Designed principally by Donato Bramante, Michelangelo, Carlo Maderno and Gian Lorenzo Bernini, St. Peter's is the most renowned work of Renaissance architecture and the largest church in the entire world.  St. Peter's is regarded as one of the holiest Catholic shrines. It has been described as "holding a unique position in the Christian world and as "the greatest of all churches of Christendom".  Catholic tradition holds that the Basilica is the burial site of Saint Peter, chief among Jesus's Apostles and also the first Bishop of Rome. Saint Peter's tomb is supposedly directly below the high altar of the Basilica. For this reason, many Popes have been interred at St. Peter's since the Early Christian period, and there has been a church on this site since the time of the Roman emperor Constantine the Great.