The national museum of Castel S. Angelo is opens on summer evenings until 8 September, with free guided tours in Italian, English, French and Spanish.

The English-language tours take place each night at 22.30 while the French and Spanish tours are available on request for groups of minimum of 10 people. Tours in Italian are held every half hour from 20.30 to 23.30.

All tours include areas usually closed to the public such as the Passetto di Borgo, an 800m-long escape passage linking the former papal fortress to the Vatican; prisons used from Renaissance times up to the 19th century; while those curious to know what a 16th-century pope’s bathroom looked like can check out the Stufetta di Clement VII.

In addition to the guided tours there are free concerts of opera, pop and classical music at 21.30 every Wednesday, Friday, Saturday and Sunday. There is also a bar and restaurant with panoramic views of the capital. Organisers say last year's summer opening attracted over 40,000 people.

For the duration of the initiative Castel S. Angelo is open daily from 20.30 until 01.00.

Tickets cost €10, children under 10 go free, and the ticket office is open until midnight. Booking tours is advised, tel. 0688522480 (Mon-Fri 10.00-18.00, Sat-Sun 15.00-18.00) or see website.