The Leaning Tower of Pisa was the result of a human mistake. Just one miscalculation made in the 11th Century left us with a unique, 14,500 ton Leaning Tower!
The construction of the Tower began in 1173 and was initially designed as a bell tower. It stood upright for over five years but began to lean when the third floor was completed in 1178. Italians were shocked by the event, as the Tower began to lean ever so slightly.
The Towers foundation, which is only 3-meters deep, was built on a dense clay mixture. This mix impacted the soil, and the clay was not strong enough to hold the Tower upright. As a result, the weight of the Tower began to diffuse downward until it had found the weakest point.
Due to this problem, construction work stopped for 100 years. The government decided to focus on its war with Genoa and hope the soil would settle in the meantime.
After 100 years, engineer Giovanni di Simone stepped forward and started to add more floors to the Tower. He tried to compensate for the original lean by making one side of the upper floors taller than the other; however, this only caused the Tower to lean more.
Unconcerned by the leaning, a 7th floor and bell tower were added to the Tower in the 14th Century. The Tower was then left on its own until the 19th Century.
In 1838, architect Alessandro Della Gherardesca dug a pathway at the base of the Tower to allow people to admire the intricately crafted base; however, this caused the Tower to lean even more.
World War II caused destruction worldwide; however, the Leaning Tower of Pisa was very lucky! In fact, when American Soldiers invaded Pisa, they were ordered to destroy all buildings to prevent enemy snipers from finding suitable places to hide. There were no exceptions to this rule, and many buildings were blown up every day as US forces advanced over the Italian countryside. However, a retreat took place shortly after the Americans' arrival, making it unnecessary to destroy the Leaning Tower of Pisa.
Twenty years after the end of the war, Italy asked for help to avoid the Leaning Tower of Pisa from toppling. They didn't want the Tower to lose its lean though, as it was now the symbol of the city and a landmark loved by tourists. As a temporary measure, engineers and architects installed a leaden counterweight of 800 tonnes*.
*A Tonne is another word for Metric Ton. One tonne is roughly equivalent to 2205 pounds
Article Information Source: https://www.romeprivateguides.com/en/blog/about-florence/the-history-behind-the-leaning-tower-of-pisa.html#:~:text=The%20Early%20Years%20of%20the,to%20lean%20ever%20so%20slightly.