The Passetto di Borgo is a secret corridor, leading from the Vatican to the Castle of Saint Angel, called also the Mausoleum of Hadrian, in Rome, Italy.
The passage was constructed in the 13th century by Pope Nicholas III's order. During the following years it was used by popes who were able to run away and hide there in case of any danger or a threat to their lives. It was also the first place in the world where an elevator was constructed in 1513, for Leon X.
From time to time the corridor is open to public and then it is possible to hear the whole story of this mysterious place ans see the historical elevator. The motif of the Passeto di Borgo was used in the book 'Angels and demons' by Dan Brown, while four abducted cardinals were transported from the Vatican to the Castle of Saint Angel.