The Porta Santa (Holy Door), the work of the Sienese sculptor Vico Consorti (1902-97), was installed in 1949.
The Porta Santais only open during a Jubilee, or Holy Year, which normally takes place every twenty-five years. For the rest of the time the door remains closed and walled up on the inside. The Holy Door represents Jesus, the Good Shepherd and the sheep pen: "I am the door: by me if any man enter in, he shall be saved, and shall go in and out, and find pasture." (John 10:9, KJV).
The sixteen bronze panels are divided by the coats of arms of popes who have celebrated Jubilee years. The panels depict scenes from the bible, apart from the bottom-right panel, which depicts Pope Pius XII (r. 1939-58) opening the Holy Door to mark the start of the 1950 Jubilee.