The church’s history dates back to early Christianity and, together with the Cloistery, the Baptistery, the Holy Steps (Scala Santa) and its Sancta Sanctorum chapel, forms a complex of remarkable interest.
As this is an archbasilica, it means that only the pope himself can celebrate mass on the church’s main altar. Above the left-hand transept you’ll see the Altar of the Sacrament. Its origin is uncertain, but it’s either been shipped from Jerusalem or it is an adaptation of the one which once stood in the magnificent (but pagan) Capitoline Jupiter temple. One of the most evocative relics is definitely the wood fragment, situated in the tympanum, which belongs to the table where Jesus had the Last Supper with the apostles.
