Notre Dame Cathedral is one of the world's five major churches. The church complex consists of cathedrals, bell towers and baptism halls. It was listed as a part of Florence's historical center in 1982 as a world cultural heritage site. Among the ancillary buildings of the cathedral, the bell tower in the southwest is the most praised in history. It was completed in three years from 1384. The 85-metre-high bell tower is covered with white, green and pink granite from Tuscany. It belongs to the Florentine Gothic style. There are 370 steps in the building, which can be climbed to overlook the whole city. The designer of the Bell Tower is no one else. It is Giotto, a great fresco contemporary with the poet Dante in the early Italian Renaissance, who is also known as Giotto Bell Tower.