This weekend nearly 700 sites that are usually off limits to visitors will open their doors as Italy celebrates its hidden cultural heritage. On October 13th and 14th the Italian National Trust, FAI, is inviting the public inside castles, villas, palaces, theatres, monasteries, underground reservoirs, gardens, workshops, old power plants, lighthouses, dams, a boat and even a train as part of its Giornate FAI ('FAI Days').

The event takes place twice a year, once in spring and once in autumn, and is designed to draw locals and tourists alike off the beaten path and towards some of Italy's lesser-known treasures. Many of the sites are ones that people will have admired from outside and longed to peek into, but others are gems that you may have walked past without even noticing – such as the street art that lines the walls by Ravenna's docks, terraces built by the Saracens in Tricarico, Matera, or the old signal room in Rome's central station.