The Leaning Tower of Pisa is 55.86 meters (183.27 feet) from the ground on the low side and 56.67 meters (185.93 feet) on the high side. The width of the walls at the base is 2.44 m (8 ft 0.06 in).
It took 199 years to build the Tower of Pisa, beginning in August 1173. The construction was stopped twice, the first time for 100 years, the second time in 1284. Both times it was due to wars.
The Leaning Tower of Pisa weighs approximately 14,500 tonnes (16,000 short tons).
The foundation of the Leaning Tower of Pisa, only three meter deep, was built on a dense clay mixture.
It is a medieval architecture, in Romanesque style.
It was built as a freestanding bell tower for the cathedral in Pisa.
The Leaning Tower of Pisa is a circular shape and has eight floors. The circular shape and great height of the campanile were unusual for their time, and the crowning belfry is stylistically distinct from the rest of the construction.
The seven bells are located on the eighth floor. Each bell represents one note of the musical major scale.
There are 294 steps on the north side and 296 steps on the south side of the tower.
The Leaning Tower of Pisa became a UNESCO World Heritage Site in 1987. Also included in this designation were the cathedral, cemetery and the baptistery.
In 2008 engineers stated that the Leaning Tower of Pisa had stopped moving. This is the first time in its history that it has not been slowly leaning further to one side.
The tower is slightly curved from the attempts by various architects to keep it from leaning more or falling over.
Engineers expect that the Leaning Tower of Pisa will remain stable for at least another 200 years. By then, in case another intervention is required, the technology available to make improvements could be far more advanced and preserve the tower for another 800 years.
The Leaning Tower of Pisa is a symbol of national pride.
The tower was closed to the public from 1989 until 2001, which reduced the tilt to 3.97 degrees.
Even a minor earthquake in the region could have devastating consequences.
Between 1589 and 1592, Galileo Galilei, who lived in Pisa at the time, is said to have dropped two cannonballs of different masses from the tower to demonstrate that their speed of descent was independent of their mass.
During World War II, the Allies suspected that the Germans were using the tower as an observation post. A US Army sergeant sent to confirm the presence of German troops in the tower was impressed by the beauty of the cathedral and its campanile, and thus refrained from ordering an artillery strike, sparing it from destruction.