The Porta Santa (Holy Door) is the smallest of the five bronze doors leading into St Peter's Basilica. The work of Vico Consorti (1902-97), the Holy Door was consecrated and opened on December 24th, 1949, by Pope Pius XII (r. 1939-58), marking the start of the Jubilee, or Holy Year, of 1950.
The door is made up of sixteen bronze panels, which depict scenes inspired by the theme of the 1950 Jubilee: 'The great return and the great pardon'. There are scenes of sin, incredulity and denial, but also of reconciliation between man and God. The bottom right panel depicts Pope Pius XII Opening the Holy Door.
The Porta Santa is only used on the occasion of a Jubilee (Holy Year), which is normally held every twenty-five years; for the rest of the time the portal is bricked up on the inside. At the start of a Jubilee the bricks are removed and the door is officially opened by the pope, who is the first to enter the basilica through it. And, at the close of the Jubilee, he is the last person to leave through it. The portal is then once again bricked up.
St Peter's Basilica is not the only church in Rome to have a Porta Santa. There are Holy Doors in the other three Papal Basilicas: Santa Maria Maggiore, San Paolo fuori le Mura and San Giovanni in Laterano (Rome's cathedral).