The passageway linking the Vatican with Castel S. Angelo is now open to the public. The corridor was built in 1277 to provide an escape route for the pope, and was most famously used by Pope Clemente VII in 1527, when he fled his palace during the sack of Rome. The bridge-like passage, which is over 600 m long and runs parallel to Via della Conciliazione along Borgo S. Angelo and Via dei Corridori, is built on two levels: an open battlement for patrols on top, and a covered tunnel below. The structure has been under restoration since 2000, and has never been open to the public before. Due to a lack of funding only some of the area is lit electrically; most of it is illuminated with oil lamps.

The corridor can be visited as part of the Notti sulle Terrazze di Castel S. Angelo festival (see What's on, Festivals), which runs every evening 21.00-11.45 until 10 Aug. If the popularity of the nocturnal visits prevails, then opening dates will be extended beyond the festival. Visits for 100 people at a time take place every 30 minutes; booking is often necessary, so check on tel. 0639967600. Admission to Castel S. Angelo is 8, plus 2 to see the corridor.