The tower of Pisa is located in Piazza dei Miracoli, next to the cathedral and is undoubtedly the main monument of the Tuscan city of the same name. Monument that over the centuries has assumed more and more importance, especially for its obvious slope. The tower is about 56 meters high, weighing 14000 tons and consists of eight floors, on which are placed seven bells, each dedicated to a time of the liturgical day: Assunta (the largest that weighs 3620 kg), Crucifix, San Ranieri, Dal Pozzo, Pasquereccia, Terza, Vespruccio, which still play today before the masses in the cathedral and at noon through an electronic system. The problems related to the structure of the tower emerged almost immediately the beginning of construction work on the same, which took place in 1173. Already with the construction of the third floor the structure began, in fact, to tilt, but the work continued until 1350. It is said that it was born from the project of Diotisalvi, already father of the Baptistery.