Not a lot of people know that: under Palazzo degli Uffici there is one of the three air-raid shelters build by Mussolini. The bunker was built between 1937 and 1939, it is 32,90m underground and it is 475 m2 wide. It was really modern for that time and it could host up to 300 people for 4 months. The other two shelters are at Villa Torlonia, the private palace of Mussolini, and at Piazza Venezia, under his office.