Why Was The Leaning Tower Of Pisa Built?

Why Was The Leaning Tower Of Pisa Built is a question that unveils a fascinating blend of ambition, architectural oversight, and historical events. At WHY.EDU.VN, we explore the complete history behind this iconic structure, offering insights into its original purpose, the missteps that led to its famous tilt, and the myriad efforts to stabilize it. Discover the complete details of the Tower of Pisa, including its design flaws and historical significance.

1. An Ambitious Beginning: Displaying Pisa’s Power

In the 12th century, Pisa experienced significant growth in its military, commercial, and political influence, transforming from a small seaport into a regional powerhouse. Like other prosperous medieval Italian cities, Pisa invested its newfound wealth in constructing grand buildings. In 1063, after sacking Palermo, the city’s government sought a place to showcase the treasures brought back from Sicily. They decided to build the “Field of Miracles,” also known as the Square of Miracles, which would eventually house a Cathedral, Baptistery, cemetery, and a towering bell tower. The bell tower was intended to be the tallest of its time.

1.1. The Vision Behind the Square of Miracles

The Square of Miracles was envisioned as a testament to Pisa’s growing power and wealth. The construction of the Cathedral, Baptistery, and cemetery were all part of a grand plan to create a monumental complex that would reflect the city’s prestige. The bell tower, later known as the Leaning Tower of Pisa, was intended to be the crowning glory of this ambitious project. It was meant to stand tall and straight, symbolizing Pisa’s prowess and architectural capabilities.

1.2. Initial Purpose of the Bell Tower

The primary purpose of the bell tower was functional. It was designed to house the bells for the adjacent Cathedral, which were essential for calling the faithful to prayer and marking important religious events. The tower’s height was intended to allow the sound of the bells to carry far and wide, reaching all corners of the city. Beyond its practical function, the tower also served as a symbol of civic pride and religious devotion.

1.3. Early Architectural Ambitions

The architects of the Leaning Tower of Pisa aimed to create a structure that would not only serve its practical purpose but also stand as a symbol of Pisa’s architectural prowess. The tower was designed with intricate details and elegant features, reflecting the artistic and engineering skills of the time. The use of high-quality materials and skilled craftsmanship was intended to ensure that the tower would endure for centuries, serving as a lasting legacy of Pisa’s golden age.

2. The Inevitable Tilt: Marshy Land and Miscalculations

Given that the name Pisa comes from the Greek word for “marshy land,” one might assume that the cathedral’s architects would have considered the subsoil when building such a tall bell tower. However, they did not. By giving the tower a shallow and relatively heavy foundation, they inadvertently doomed it from the outset. The tower began to sink on one side while the second story was being built, by then, it was too late to turn back.

2.1. The Role of the Subsoil

The soil beneath Pisa is composed of soft clay, sand, and shells, making it unstable and prone to shifting. This type of subsoil is particularly unsuitable for supporting heavy structures, especially those with shallow foundations. The architects failed to adequately assess the soil conditions, leading to the tower’s gradual sinking and tilting.

2.2. The Foundation’s Flaws

The foundation of the Leaning Tower of Pisa was only three meters deep, which was insufficient for a structure of its size and weight. This shallow foundation exacerbated the problem of the unstable subsoil, causing the tower to sink unevenly. The weight of the tower was not distributed evenly across the foundation, further contributing to the tilt.

2.3. First Signs of Trouble

The first signs of the tower’s instability appeared when construction reached the second story. As the builders added more weight to the structure, it began to sink noticeably on the south side. This sinking caused the tower to lean, and it became clear that the initial architectural plans had failed to account for the soil conditions.

3. Attempts at Correction: Centuries of Engineering Missteps

As construction continued, the builders tried to correct their mistake by adding taller columns and arches on the south side of the tower. By the time they reached the fourth story (out of a planned eight), they had to make the arches on the south side a full two inches taller than those on the north, and the tower still continued to lean. Unsure of what to do next, the builders halted construction for almost a century.

3.1. Early Corrective Measures

The initial attempts to correct the lean involved adding taller columns and arches on the south side of the tower. The builders hoped that by increasing the height of these structural elements, they could counteract the sinking on that side. However, these efforts proved to be largely ineffective.

3.2. Pauses in Construction

The construction of the Leaning Tower of Pisa was marked by several lengthy pauses. After realizing the severity of the lean, the builders halted construction for nearly a century. This pause was intended to allow the soil to settle and to give engineers time to devise a solution. However, when construction resumed, the tower continued to lean.

3.3. The Impact of Continued Construction

Despite the challenges posed by the lean, the builders continued to work on the tower. As they added more stories, the weight of the structure increased, exacerbating the problem of the unstable subsoil. The tower’s center of gravity shifted, causing it to lean in different directions at various points during construction.

4. Not Alone: Other Leaning Towers in Pisa

Due to the soft subsoil of the entire area, there are actually several leaning towers of Pisa. You can see two others in Pisa’s Borgo Stretto. The bell tower of the Church of St. Nicola is perhaps the most famous, after the official Leaning Tower of Pisa. Built around the same time as the tower, in 1170, this octagonal bell tower also boasts a slight but unmistakable slouch. There’s also the bell tower at the church of St. Michele degli Scalzi, located on Viale delle Piagge. Actually, the name “Piagge” comes from the Latin for “low plains prone to flooding.”

4.1. The Church of St. Nicola

The bell tower of the Church of St. Nicola, built around 1170, is another example of a leaning structure in Pisa. This octagonal tower, like the Leaning Tower of Pisa, suffers from the same unstable subsoil conditions. Its slight but noticeable slouch is a testament to the widespread challenges of building on Pisa’s marshy land.

4.2. The Church of St. Michele degli Scalzi

The bell tower at the Church of St. Michele degli Scalzi, located on Viale delle Piagge, also leans due to the area’s soft soil. The name “Piagge,” derived from the Latin term for “low plains prone to flooding,” underscores the historical awareness of the region’s susceptibility to ground instability. Despite this knowledge, the tower was constructed, and it too began to lean over time.

4.3. Common Causes of Leaning Structures

The presence of multiple leaning towers in Pisa highlights the underlying issue of the area’s unstable subsoil. The composition of soft clay, sand, and shells makes the ground prone to shifting, causing structures to sink unevenly. This phenomenon is not unique to Pisa, as other cities built on similar soil conditions have also experienced problems with leaning buildings.

5. A Shifting History: Multiple Directions of the Lean

Over hundreds of years, multiple engineers tried to correct the famous lean with little to no success. When construction began again on the third story, in the 13th century, engineers tried to stop the tilt by building straight upwards, but the center of gravity was thrown off and the tower simply began to lean in a different direction. As construction continued, the tower eventually settled back into its southward tilt, where it has stayed ever since.

5.1. Attempts to Build Straight Upwards

In the 13th century, when construction resumed on the third story, engineers attempted to counteract the lean by building straight upwards. They hoped that by aligning the upper stories vertically, they could correct the tower’s tilt. However, this approach shifted the center of gravity, causing the tower to lean in a different direction.

5.2. The Inevitable Return to the Southward Tilt

Despite the efforts to correct the lean, the tower eventually settled back into its southward tilt. The unstable subsoil continued to exert its influence, causing the tower to sink unevenly. The weight of the structure and the shifting ground made it difficult to achieve a stable equilibrium.

5.3. The Ongoing Challenge of Stabilization

The Leaning Tower of Pisa has presented engineers with an ongoing challenge of stabilization. Over the centuries, various methods have been proposed and implemented, but none have been entirely successful in eliminating the lean. The complexity of the problem requires a deep understanding of soil mechanics, structural engineering, and historical construction techniques.

6. The Numbers Game: Imbalances and Inclinations

The leaning tower of Pisa was supposed to be 60 meters tall (196.85 feet). After the lean, however, the highest side of the tower reaches a mere 56.67 meters (about 186 feet), while the lowest side is 55.86m, or 183 feet. By 1990, the tower had reached a tilt of 5.5 degrees, nearly 15 feet from its base, and enough to topple it over, by most calculations! Luckily, this considerable tilt was enough to overcome the world-famous inertia of Italian bureaucracy and kick start a massive restoration program that reduced the tilt to only 3.97 degrees. Because of the tower’s original list, the north side staircase has something like 296 steps to the top, while the south side has just 294.

6.1. Height Discrepancies

The original design of the Leaning Tower of Pisa called for a height of 60 meters (196.85 feet). However, due to the lean, the highest side of the tower now reaches only 56.67 meters (about 186 feet), while the lowest side measures 55.86 meters (183 feet). This discrepancy in height is a direct result of the tower’s uneven sinking and tilting.

6.2. The Critical Tilt of 1990

By 1990, the Leaning Tower of Pisa had reached a tilt of 5.5 degrees, which placed it nearly 15 feet off its base. This level of inclination was considered critical, as experts warned that the tower was at risk of collapse. The severity of the situation prompted a large-scale restoration effort aimed at reducing the tilt and stabilizing the structure.

6.3. The Staircase Anomaly

The lean of the Leaning Tower of Pisa has also resulted in an unusual feature: the number of steps on the north and south sides of the staircase is different. The north side has approximately 296 steps to the top, while the south side has only 294. This difference is due to the uneven height of the tower, caused by the sinking and tilting.

7. Unforeseen Saviors: War, Debt, and Time

Debt and war typically have not been boons to great construction projects in Italy, but in the case of the Leaning Tower of Pisa, they may have just been a saving grace. Some structural engineers theorize that continued delays in construction over 200 years may have given the soil underneath the already-slightly-leaning tower time to compress, ultimately saving it from toppling over.

7.1. The Role of Construction Delays

The prolonged delays in the construction of the Leaning Tower of Pisa may have inadvertently contributed to its survival. Over a period of more than 200 years, the soil beneath the tower had time to compress and consolidate. This natural process of soil stabilization may have helped to prevent the tower from collapsing.

7.2. War and Economic Strife as Stabilizers

Wars and economic hardships often disrupt construction projects, but in the case of the Leaning Tower of Pisa, they may have served as unforeseen stabilizers. The interruptions in construction allowed the soil to settle and adapt to the weight of the structure, potentially mitigating the risk of collapse.

7.3. The Unintended Benefits of Setbacks

The history of the Leaning Tower of Pisa is filled with setbacks and challenges, but these obstacles may have ultimately contributed to its resilience. The delays, miscalculations, and engineering missteps created a unique set of circumstances that allowed the tower to survive for centuries.

8. Climbing the Icon: A Visitor’s Perspective

The most famous structurally unsound building in the world is open to visitors. Since its restoration and slight un-tilting, the structure’s integrity is monitored constantly. The building hosts large numbers of visitors every day, so if you want to climb to the top, you should book tickets in advance.

8.1. Access to the Tower

Despite its structural challenges, the Leaning Tower of Pisa is open to visitors who wish to climb to the top. The opportunity to ascend this iconic structure offers a unique perspective on its history, architecture, and the surrounding landscape. However, due to the tower’s popularity and the limited number of people allowed inside at any given time, it is essential to book tickets in advance.

8.2. Safety Measures and Monitoring

The structural integrity of the Leaning Tower of Pisa is continuously monitored to ensure the safety of visitors. Advanced sensors and monitoring equipment track the tower’s movement, tilt, and any potential signs of instability. These measures allow engineers to detect and address any issues promptly, ensuring that the tower remains safe for public access.

8.3. The Experience of Climbing the Tower

Climbing the Leaning Tower of Pisa is a memorable experience that provides a unique perspective on its architectural challenges and historical significance. As visitors ascend the winding staircase, they can feel the tower’s tilt and appreciate the ingenuity of the engineers who have worked to preserve it. The view from the top offers a panoramic vista of Pisa and the surrounding countryside.

9. Silent Bells: A 20th-Century Decision

Each of these large bells (the largest weighs nearly 8,000 pounds) represents a musical note from the major scale. Even though you can still see them if you climb to the top of the tower, they haven’t tolled since the 20th century. By now, you can probably guess why. Restorers and engineers worried that their movements would make the tower lean even more.

9.1. The Tower’s Seven Bells

The Leaning Tower of Pisa is home to seven large bells, each representing a musical note from the major scale. These bells were originally intended to be rung to mark important religious events and call the faithful to prayer. The largest of these bells weighs nearly 8,000 pounds, and their combined weight and movement could potentially affect the tower’s stability.

9.2. The Decision to Silence the Bells

In the 20th century, engineers and restorers made the decision to silence the bells of the Leaning Tower of Pisa. They were concerned that the movement of the bells could exacerbate the tower’s lean and potentially contribute to its instability. This decision was made as part of a larger effort to preserve and protect the tower for future generations.

9.3. The Impact on the Tower’s Function

The silencing of the bells has had a significant impact on the tower’s function. While the bells are still visible to visitors who climb to the top, they no longer serve their original purpose of marking time and calling the faithful to prayer. The decision to prioritize the tower’s stability over its traditional function reflects the ongoing challenge of preserving this iconic structure.

10. Mussolini’s Misguided Attempt: Making Matters Worse

Italy’s 20th-century dictator, Benito Mussolini, was ashamed of the Leaning Tower of Pisa. He considered its mistaken construction and subsequent lean a national disgrace, an embarrassment to Italy’s reputation. So, as with many of the things that he considered shortcoming of Italy, he set out to fix it. Unlike some of his other projects, like draining the swamps of Sicily, it didn’t go well. The idea was to drill hundreds of holes in the base of the tower and pump in grout and mortar to, essentially, ballast the entire structure and set it straight. In reality, all this accomplished was to create an even heavier base that made the tower lean even more than it had before.

10.1. Mussolini’s Disdain for the Tower

Benito Mussolini, the 20th-century dictator of Italy, viewed the Leaning Tower of Pisa with disdain. He considered its flawed construction and subsequent lean a national embarrassment, tarnishing Italy’s reputation. Mussolini was determined to rectify what he saw as a symbol of Italian inadequacy.

10.2. The Ill-Fated Intervention

In an attempt to correct the lean, Mussolini ordered engineers to drill hundreds of holes in the base of the tower and pump in grout and mortar. The intention was to ballast the structure and set it straight. However, this intervention proved to be disastrous.

10.3. The Unintended Consequences

Mussolini’s misguided attempt to fix the Leaning Tower of Pisa had the opposite effect. The added weight of the grout and mortar only exacerbated the lean, causing the tower to sink further into the unstable subsoil. The intervention was a significant setback in the efforts to stabilize the tower.

11. Averting Destruction: WWII and the Tower’s Salvation

American soldiers had orders to tear down any and all buildings in Italy that could serve as lookout points, or “nests,” for enemy snipers during World War Two. In fact, the Germans who were occupying Italy at the time did often use the tower as a lookout, but it’s said that when the Allies arrived they were so impressed by the beauty of the Leaning Tower of Pisa and the surrounding Field of Miracles that they decided not to level the area.

11.1. The Tower as a Potential Target

During World War II, the Leaning Tower of Pisa was at risk of destruction. American soldiers had orders to demolish any buildings in Italy that could be used as lookout points by enemy snipers. The Germans, who were occupying Italy at the time, often used the tower as a strategic vantage point.

11.2. The Allies’ Decision to Spare the Tower

When the Allied forces arrived in Pisa, they were reportedly so impressed by the beauty of the Leaning Tower of Pisa and the surrounding Field of Miracles that they decided not to destroy the area. This decision spared the tower from potential demolition and preserved it for future generations.

11.3. The Tower’s Cultural Significance

The Leaning Tower of Pisa’s cultural significance played a crucial role in its salvation during World War II. The tower’s iconic status and architectural beauty resonated with the Allied soldiers, who recognized its importance as a historical landmark. This recognition ultimately led to the decision to spare the tower from destruction.

12. Stability Achieved: The 21st-Century Solution

The tower has survived centuries of well-meaning but misguided attempts to right it, including various engineers who added levels and arches of all different heights, and one overzealous group who dug around the tower to open an underground tour (which only helped to fill the area with even more water). But someone finally got it right in the 21st century, and as of 2001, the tower was officially declared stable for at least the next 200 years. In 2008 engineers found that the tower is officially no longer moving. The first time in its history that it hasn’t been slowly listing to one side. 200 years from now, let’s just hope we have the technology to save the tower for another 200.

12.1. The Successful Stabilization Efforts

After centuries of failed attempts, engineers finally achieved a breakthrough in the 21st century. A series of innovative stabilization techniques were implemented, including soil extraction and the installation of underground anchors. These efforts successfully reduced the tower’s lean and ensured its stability for the foreseeable future.

12.2. The Tower’s Declared Stability

In 2001, the Leaning Tower of Pisa was officially declared stable for at least the next 200 years. This announcement marked a significant milestone in the preservation of the tower and provided reassurance that this iconic structure would endure for generations to come.

12.3. Continuous Monitoring and Maintenance

Despite the success of the stabilization efforts, the Leaning Tower of Pisa remains under continuous monitoring and maintenance. Engineers regularly inspect the tower for any signs of instability and implement preventative measures to ensure its long-term preservation. This ongoing commitment to the tower’s care is essential for safeguarding its future.

13. Why the Leaning Tower of Pisa Captivates Us

13.1 A Testament to Human Endeavor

The Leaning Tower of Pisa is a monument to human inventiveness, resilience, and adaptation, not just an architectural marvel. The tower’s existence now is a result of the countless individuals who dedicated their time and effort to saving it from inevitable collapse, from the first architects who began construction in the 12th century to the contemporary engineers who stabilized it in the 21st. It stands for our capacity to discover answers to even the most difficult issues and to work together to safeguard our cultural legacy for coming generations.

13.2. The Beauty in Imperfection

The Leaning Tower of Pisa represents a departure from traditional notions of perfection in architecture and design. The tower welcomes the beauty of imperfection with its well-known lean, reminding us that uniqueness and charm can arise from unexpected sources. Its flaw enhances its allure, drawing people in with its distinctive character and causing them to consider the value of embracing what makes us unique.

13.3. A Reminder of History

The Leaning Tower of Pisa is a reminder of the past and is more than just a historical landmark. Its history is entwined with the economic, political, and cultural forces that have influenced Pisa and Italy for many centuries. From its beginnings as a sign of Pisa’s wealth and power to its near destruction during World War II, the tower has seen some of history’s most important events unfold. We can gain insightful knowledge about the past by looking at the tower, which encourages us to value our shared history and consider the lessons we can draw from it.

14. Frequently Asked Questions (FAQs)

1. Why does the Leaning Tower of Pisa lean?

   The Leaning Tower of Pisa leans because it was built on unstable subsoil composed of soft clay, sand, and shells, which caused the tower to sink unevenly.

2. When did the construction of the Leaning Tower of Pisa begin?

   The construction of the Leaning Tower of Pisa began in 1173.

3. How tall is the Leaning Tower of Pisa?

   The highest side of the Leaning Tower of Pisa reaches 56.67 meters (about 186 feet), while the lowest side is 55.86 meters (183 feet).

4. What was Mussolini’s involvement with the Leaning Tower of Pisa?

   Mussolini attempted to correct the lean by drilling holes and pumping in grout and mortar, but this only made the tower lean more.

5. Was the Leaning Tower of Pisa in danger of collapsing?

   Yes, by 1990, the tower had reached a tilt of 5.5 degrees, nearly 15 feet from its base, which was considered enough to topple it over.

6. What measures were taken to stabilize the Leaning Tower of Pisa?

   Engineers implemented soil extraction and installed underground anchors to reduce the lean and stabilize the tower.

7. Is it possible to climb the Leaning Tower of Pisa?

   Yes, the Leaning Tower of Pisa is open to visitors who wish to climb to the top, but it is essential to book tickets in advance.

8. Why were the bells of the Leaning Tower of Pisa silenced?

   The bells were silenced in the 20th century because engineers worried that their movement would make the tower lean even more.

9. When was the Leaning Tower of Pisa declared stable?

   The Leaning Tower of Pisa was officially declared stable in 2001 for at least the next 200 years.

10. How many steps are there in the Leaning Tower of Pisa?

    The north side staircase has about 296 steps, while the south side has about 294 steps, due to the tower’s lean.

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