The Leaning Tower of Pisa stands as a global symbol of accidental beauty. While millions of tourists pose for photos to "hold it up," the tower itself hides a history of engineering failure and survival. For instance, the ground underneath it is essentially a marsh that nearly caused a collapse during construction. Furthermore, a brave soldier saved it from destruction during a world war because he found it too beautiful to bomb. Prepare to climb the 294 steps of the Rose City’s cousin.
Leaning Tower of Pisa
It was never supposed to lean. The architects originally designed a perfectly vertical bell tower for the neighboring cathedral. However, they built it on a shallow foundation of only three meters. Consequently, the soft, marshy soil of clay and sand began to shift under the weight.
The tower is actually curved like a banana. Engineers noticed the tilt during the construction of the third floor. To compensate, they built the remaining floors with one side taller than the other. Thus, the structure has a slight curve because they tried to “straighten” it as they went up.
It took nearly 200 years to finish Leaning Tower of Pisa. Construction began in 1173 but stopped multiple times due to wars with nearby cities like Florence and Genoa. These long delays actually saved the tower. Specifically, the pauses allowed the underlying soil to settle and compress under the weight.
The name “Pisa” comes from a Greek word meaning “marshy land.” The soil composition consists of layers of sand, shells, and silt. Therefore, the ground behaves more like a liquid than solid rock. Interestingly, several other towers in the city also lean for this exact reason.
Legend says Galileo used it for his most famous experiment. According to his secretary, the scientist dropped two cannonballs of different masses from the top. He wanted to prove that objects fall at the same speed regardless of weight. However, many historians believe this story is a charming myth.
An American soldier saved it from an artillery strike. During World War II, the Allies suspected the Germans used the tower as an observation post. A young sergeant had orders to call in a strike to destroy it. Nevertheless, he hesitated because the beauty of the square moved him, and the tower survived.
Benito Mussolini hated the lean. The Italian dictator considered the tower an embarrassment to the nation. He ordered workers to pump 80 tons of concrete into the foundation to straighten it. Unfortunately, this heavy addition caused the tower to sink even further into the mud.
The belfry houses seven massive bells. Each bell represents a different note on the musical major scale. The largest bell, called L’Assunta, weighs over three tons. Currently, the bells remain silent because engineers fear their vibrations could destabilize the structure.
The thirteenth capsule does not exist. Like many superstitious buildings, the tower avoids the number thirteen. While there are 32 levels of arches, the numbering system for specific architectural features often skips the unlucky figure.
Leaning Tower of Pisa survived four major earthquakes. Despite its precarious angle, the soft soil that caused the lean also acts as a shock absorber. This “dynamic soil-structure interaction” prevents the tower from resonating with the seismic waves that destroy more rigid buildings.
The lean was once much worse than it is today. By 1990, the tower tilted at a dangerous 5.5 degrees. Experts warned it was on the verge of collapse. Consequently, the government closed it for a decade to perform a 200-million-euro stabilization project.
Engineers used giant lead weights to steady it. During the restoration, they placed 800 tons of lead on the northern side to act as a counterweight. Later, they carefully removed soil from underneath the high side to gently “pull” the tower back toward the center.
The height of the tower is different on each side. Because of the tilt, the low side measures 55.86 meters while the high side reaches 56.67 meters. Therefore, you are technically taller or shorter depending on which side of the belfry you stand on.
Leaning Tower of Pisa is moving back toward a vertical position. Since the restoration in 2001, the tower has continued to straighten itself by a few centimeters. Experts predict it will remain stable for at least another 300 years before it needs more help.
Finally, the true architect remains a mystery. For centuries, people credited Bonanno Pisano or Guglielmo. However, recent evidence suggests Diotisalvi, who built the nearby Baptistery, might have designed it. Thus, the creator of the world’s most famous tower remains unknown.
