The Leaning Tower of Pisa (Pisa in Tuscany, Italy) is the most famous leaning building in the world. Its height is 55.8 m, its weight is 14,500 tons, and the degree of deviation from the vertical is up to 4 degrees. 1173 August 9 construction of the Leaning Tower of Pisa began. It is not known exactly who was the architect of the tower, Bonanius Piziečius is credited with a significant contribution to the construction of the tower.

1178 the works stopped, because the tower built on the alluvial soil began to lean little by little. The first three floors sloped 0.5 degrees to the north, and the floor where the servants’ quarters were supposed to be was not built so that the axis of the structure passed through it. For Giovanni di Simone 1272-1278. built three more floors.

After the collapse of the third to sixth floors, the tower began to lean in the other direction – it tilted 0.5 degrees to the south. Later, the construction work was delayed by the Wars of Pisa and Genoa. XIV century at the beginning, the tower still did not have the upper part, where the belfry was to be installed. This part in 1360-1370 completed by architect Tomaz Pizanas.