Once you reach the Sistine Chapel, you’ll be able to access the “Secret of Secrets” safe. Head to the west end of the chapel and look for the door to the left of the altar. Head into that ...

The safe is located just off the first main area you're permitted to explore once you enter the Vatican proper, not too far from Antonio's office. Finding it begins a quest called "Secret of ...

The Indiana Jones Secret of Secrets safe code has you finding a combination from a planetary chart and two saint statues, Peter and Paul in this mystery. While you have all the info, more or less ...