There are more than 50,000 events taking place across Europe, but Italy is surely the best place to enjoy the cultural weekend, with more Unesco World Heritage sites than any other country, plus plenty of undiscovered gems.
Over 380,000 people took part in the event last year, which was created to promote cultural dialogue between the European nations.
Some sites which are usually closed will open their doors to the public for a rare glimpse, while others will be putting on special events for the occasion. Many of the most famous hotspots are staying open late, with a mere €1 fee for a nighttime visit.
In Campania, both the ruined cities of Pompeii and its lesser-known but equally impressive cousin Herculaneum are participating in the scheme, along with Naples' archeological museum which houses many of the items found in the ruins.
In Lazio, culture vultures will be spoilt for choice between the Villa Adriana and Villa d'Este in Tivoli, the Etruscan Museum and Castel Sant'Angelo among others.
In Tuscany, the Uffizi art gallery and home of Michelangelo's David, Galleria dell'Accademia, are both open until 11, as well as the Carthusian monastery of Calci in the province of Pisa and the Pinocchio-themepark in the village of Collodi.
For a full list of museums and sites participating in the Heritage weekend, check the Ministry of Cultural Heritage's website.