A city in Tuscany; site of the famous Leaning Tower.
City in Tuscany, Italy; It has an 11th–12th-century cathedral. Its famous campanile, the Leaning Tower of Pisa (repaired 1990), is 55 m/180 ft high and about 5 m/16.5 ft out of perpendicular. It has foundations only about 3 m/10 ft deep.
Pisa was a maritime republic in the 11th–12th centuries. The university dates from 1338. The scientist Galileo was born here.
Work began on the city's famous tower in 1174, and it started to tilt when only 10.6 m high. Attempts were made to straighten the tower by constructing the upper levels with blocks of marble of varying width, and by the 10th floor the blocks were 10 cm thicker on the north side than on the south.
The tower presently leans 5.5 degrees from the vertical on the north side and 2.5 m on the south, though the angle varies throughout the day because the tower is affected by the heat of the Sun. In 1990 the Italian government set up a program to reduce the tower's tilt by 10%.