Why the Tower of Pisa was Built?

The Leaning Tower of Pisa or in Italian, “Torre Pendente di Pisa”, is one of the most historic and iconic structures found in Italy. They started to build the tower in August of 1173. However, its construction was interrupted for quite some time due to a series of wars. The engineers of the tower also ran into other issues which was figuring out how to stop the tower from leaning.

The tower was eventually finished in 1399 after over 200+ years in construction. The identity of the person who originally designed the Leaning Tower remains unknown but the architect that is said to have finished the work was Tommaso Pisano.

The tower of Pisa was originally designed to be the city’s bell tower. Pisa back then was a simple city solely known as an important Italian seaport. During the Pisans attack on the City of Palermo, they succeeded and took control.

As a memoir of their success and to let the world know how important the city was, the people of Pisa decided to build a grand complex that they have called Campo de Miracoli or “The Field of Miracles.” The Grand Complex’s plan comprised of a cathedral, baptistery, a cemetery, and the bell tower now known as the Leaning Tower of Pisa.


Why the Tower of Pisa leaned?

It wasn’t originally designed to lean, but because of the soft soil it was built on it begun to lean as contractors began to construct the 3rd story of the tower in the year 1178. The additional construction of the tower shook the tower’s center of gravity, causing it to tilt to the other side.

As the engineers carried on to build the 4th, 5th, 6th, and its 7th stories, the north side of the tower that was leaning began tilting the other direction, now leaning southward. The architects and engineers of the Tower of Pisa tried to correct this by making the remaining stacks of the tower smaller on a uphill slant, but it didn’t do anything to prevent it from leaning still.

The construction of the tower was failing because of the foundation that wasn’t strong enough to support the structure. The soil which served as the foundation is composed merely of soft materials-fine sand, clays, and shells.

The engineers tried to compensate the lean through building the short side higher, but to no avail, the additional floors only made the tower lean and sink more. Over the years the 55-meter bell tower clearly wasn’t leaning but actually sinking an average of one to two millimeters per year.

Restoration and Foundation balancing projects for the Tower

Time passes and the ground the tower stands on, weakens even more. A 0.2 tilt grew fast over the years and is now at the maximum tilt vertical of 5.5-degrees. Over the next few decades, many teams of engineers tried to level the soil where the tower stands.

They have tried anchoring mechanisms where it only provided a more secure stance but had no luck in stabilizing the tower’s continuous lean. In 1932, an Italian named Mussolini attempted to fix the tower by ordering his men to drill holes into the tower and pump in grout. This only made the Tower sink more due to the extra weight.

The Leaning Tower of Pisa became a UNESCO World Heritage Site in the year 1987. From 1989 to 2001 the tower was closed for restoration.

The first restoration attempt UNESCO tried failed, but their hopes were high upon the second attempt. The restoration project in 2008 was a success and put a halt to the tower’s continuous lean. It is said that the tower can now withhold for at least another 200 years.

Some experts, however, say that the tower might continue sinking. There is no assurance that the balancing of its foundation can justify that it can remain its stance for another 200 years like they’ve predicted. The engineers are trying their hardest make sure we do not lose one of the world’s greatest historic structures.

Measurement of the Tower

The original height of the Tower of Pisa was at 60 meters. Now the tower’s height is at 56.67 meters on the higher side and 55.86 meters on the shorter side. Its outside diameters at the base are approximately 15.484 meters, and the width of its walls at the base is 2.4384 meters.


  • The weight of the Tower of Pisa is approximately 14,500 tons.
  • There are a total of 297 steps to get from the bottom to the top.
  • Its 7 Bells are located at the 7th story of the tower.

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