On the place where had been buried Peter the apostle, father of the Catholic Church and the holder of Paradise keys, was built the Cathedral of St.Peter (San Pietro), which has always been the main pilgrimage destination for Christians.

The first basilica built by Constantine was already the greatest christian church, preceded by a wide square cloister on whose center there was a big fountain. The current complex of St.Peter belongs to the total reconstruction of the old basilica done starting from Renaissance Age.

Nowadays you enter to St. Peter from Via della Conciliazione (Reconcilement Avenue), result of a town rearrangement done in the XIX century, that flatter the facade of the cathedral on the background, but formerly the streets around the Vatican where narrow and winding, so people had a strong visual impact while entering the wide square through the high colums made by Bernini in XVII century.

The most characterizing element of St. Peter's Cathedral is the dome, materpiece by Michelangelo Buonarroti, who also planned the whole first version of the basilica, extending an original idea by Bramante. The cathedral was enlarged during the XVII century, modifying the plan from Greek Cross to Latin Cross and building the new facade, a work by Carlo Maderno. The sculpture decoration is by Gian Lorenzo Bernini. The dome was completed by the architects Giacomo della Porta and Domenico Fontana following strictly the schemes by Michelangelo.

The interior of the cathedral has many masterpieces, among which: the Pieta by Michelangelo; the monument to Clement XIII by Antonio Canova; the St.Peter's Chair by Gian Lorenzo Bernini; the monument to Paul III by Guglielmo della Porta; the statue of St. Peter by Arnolfo di Cambio; the monument to Innocenzo VIII by Antonio del Pollaiolo; the controversial baldachin by Bernini built with the bronze taken from the Pantheon. Finally there are the Vatican Museums, whose contents it is impossible to list.