Square of the Miracles (Pisa)

The tower began to tilt as soon as construction began in August 1173. Its height is 55.7 meters from the base, its weight is estimated at 14 700 tons and the inclination of about 4 °.

The inner spiral staircase has 294 steps. It is considered, next to the cathedral of which it is part, one of the jewels of Romanesque art.