Galileo Galilei is said to have dropped two cannon balls of different masses from this tower to demonstrate that their descending speed was independent of their mass. This story, though reported by Galileo's own
student, is widely considered to be a myth.
In 1838 the architect Alessandro Della Gherardesca excavated a walkway around the tower to make the base of the tower visible again. This caused a flooding of the base and
again an increase in the inclination.
Benito Mussolini ordered the tower be returned to a vertical position, so concrete was poured into its foundation. The results were unexpected and sank the tower further into the
During World War II, the U.S. army destroyed nearly all towers in Pisa due to the potential threat from snipers. The Leaning Tower was scheduled to be blown up as well; a last-minute order to retreat prevented
On February 27, 1964, the government of Italy requested aid in preventing the tower from toppling. A multinational task force of engineers, mathematicians and historians was assigned and met on the
Azores islands to discuss stabilization methods. After over two decades of work on the subject, the tower was closed to the public in January 1990. In the time that the tower was closed the bells were removed to relieve some
weight and cables were cinched around the third level and anchored several hundred meters away. Apartments and houses in the path of the tower were vacated for safety concerns. After a decade of corrective reconstruction and
stabilization efforts the tower was reopened to the public on December 15, 2001. Many methods were proposed to stabilize the tower including the addition of 800 metric tons of lead counterweights to the raised end of the base.
The final solution to correcting the lean was to remove 38 m³ of soil from underneath the raised end. The tower has been declared stable for at least another 300 years.
- Geographic coordinates: 43.7231° N 10.3964° E
- Elevation of Piazza dei Miracoli: about 2 metres (6 feet, DMS)
- Height: 55.863 metres (183 ft 3 in), 8 stories
- Outer diameter of base: 15.484 m
- Inner diameter of base: 7.368 m
- Weight: 14,700 tonnes
- Thickness of walls at the base: 8 ft (2.4 m)
- Direction of lean: 1173-1250 north, 1272-1997 south
- Total number of bells: 7, tuned to musical scale, clockwise
- 1st bell: L'assunta, cast in 1654 by Giovanni Pietro Orlandi, weight 3,620 kg (7,981 lb)
- 2nd bell: il Crocifisso, cast in 1572 by Vincenzo Possenti, weight 2,462 kg (5,428 lb)
- 3rd bell: San Ranieri, cast in 1719-21 by Giovanni Andrea Moreni, weight 1,448 kg (3,192 lb)
- 4th bell: La Terza (1st small one), cast in 1473, weight 300 kg (661 lb)
- 5th bell: La Pasquereccia, cast in 1262 by Lotteringo, weight 1,014 kg (2,235 lb)
- 6th bell: il Vespruccio (2nd small one), cast in the fourteenth century and again in 1501 by Nicola di Jacopo, weight 1,000 kg (2,205 lb)
- 7th bell: Del Pozzetto, cast in 1606, weight 652 kg (1,437 lb)
- Steps to bell tower: 294