You’ve seen the photos. Everyone has. That one friend—or maybe it was you—standing in the Piazza dei Miracoli, arms outstretched, pretending to hold up a massive cylinder of white marble. It’s a classic. But while we all know the tower leans, and we all know it’s in Italy, surprisingly few people can actually tell you who designed the Leaning Tower of Pisa.
It’s a bit of a historical "whodunnit."
Think about it. If you built a monument that started sinking before you even finished the third floor, would you want your name on the blueprints? Probably not. For centuries, the identity of the original architect was shrouded in mystery, buried under layers of medieval pride, professional embarrassment, and a lack of surviving paperwork. It’s not like today where every skyscraper has a lead architect with a PR firm and a LinkedIn profile. In 1173, when the first stone was laid, it was a group effort funded by the spoils of war.
The Long-Running Mystery of the Architect
For the longest time, the history books pointed a finger at Guglielmo and Bonanno Pisano. Giorgio Vasari, the famous 16th-century biographer who basically invented art history, was the one who first floated Bonanno’s name. Vasari was great at storytelling, but he wasn't always a stickler for cold, hard facts. He wrote his accounts hundreds of years after the tower’s foundation was dug.
Because Bonanno was a well-known local bronze caster—the guy responsible for the stunning bronze doors on the nearby Cathedral—it made sense to people. "Oh, he's the famous guy from that era, he must have done it," was the general vibe.
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But then, the plot thickened.
In the 1820s, a piece of a cast was found at the base of the tower bearing Bonanno’s name. Case closed, right? Not exactly. Experts later realized that the inscription likely belonged to those bronze doors, not the tower’s structural design itself. It was a classic case of historical misdirection.
So, Who Really Designed the Leaning Tower of Pisa?
Recent evidence has shifted the spotlight significantly. In 2019, a massive breakthrough occurred. Giulia Ammannati, a scholar of Latin paleography at the Scuola Normale Superiore di Pisa, re-examined a stone inscription that had been sitting in the Opera della Primaziale Pisana for decades. It was a messy, hard-to-read scrap of stone.
Basically, the inscription was a bit of a boast. It roughly translated to: "I, Bonanno Pisano, have built this marvelous work."
Ammannati’s research suggests that Bonanno wasn't just the bronze guy; he was indeed the primary architect who kicked off the project in August 1173. But here’s the kicker: he was so ashamed when the thing started tilting that he supposedly ditched the project. He didn't want his legacy tied to a sinking pile of marble. He left the inscription unfinished and shoved it aside.
It’s kinda tragic when you think about it. The very thing that made him a "failure" in the 12th century is why millions of people fly to Tuscany today.
It Wasn't Just One Person
We talk about "the architect" as if one person sat down and saw the project through. That’s just not how medieval cathedrals worked. These things took lifetimes. The tower took nearly 200 years to finish.
Construction stopped and started like a bad car engine.
- Phase One (1173-1178): Bonanno Pisano starts the work. They get to the third floor, and the tower begins to settle into the soft, silty soil. Construction halts. This pause was actually a blessing. If they had kept going, the tower would have likely toppled over entirely. The 100-year break allowed the soil to compress.
- Phase Two (1272): Giovanni di Simone steps up. He's the one who tried to fix the lean by building the upper floors with one side taller than the other. This is why the tower isn't just leaning; it’s actually curved. It’s shaped like a banana. Honestly, his "fix" didn't really work, but it kept the dream alive.
- Phase Three (1319-1372): Tommaso di Andrea Pisano finally finishes the bell chamber.
So, when you ask who designed the Leaning Tower of Pisa, you're really asking about a relay race of architects, most of whom were just trying to stop a disaster from happening on their watch.
Why Did It Lean in the First Place?
You can’t talk about the designers without talking about their massive oversight. The name "Pisa" comes from a Greek word meaning "marshy land."
The ground is a nightmare for engineers.
It’s a mix of clay, fine sand, and shells. The foundations the architects designed were only three meters deep. For a tower that’s over 55 meters tall and weighs 14,500 metric tons? That’s like trying to balance a broomstick on a sponge. It was never going to end well.
The Modern "Designers" Who Saved It
If we only look at the medieval guys, we miss the people who actually kept the tower standing into the 21st century. By the late 1980s, the lean was getting dangerous. It was tipping at an angle of 5.5 degrees. Calculations showed that the tower should have already fallen over. It was a miracle of physics—or just pure luck—that it was still upright.
Enter John Burland.
Burland was a soil mechanics expert from Imperial College London. He and a team of international experts spent the 1990s trying to figure out how to "un-lean" it just enough to be safe, without losing the iconic tilt that brings in the tourists. They didn't use jacks or cables to pull it up. That would have been too risky.
Instead, they used "soil extraction." They carefully drilled out small amounts of earth from underneath the northern side (the high side). Slowly, gravity did the work. The tower settled back into a safer position.
It was a brilliant, subtle bit of engineering. They didn't "fix" the mistake; they just managed it. Today, the tower is stable, and experts say it won't move significantly for at least another 200 to 300 years.
Common Misconceptions About the Design
People love a good myth. You might hear that the lean was intentional. That’s nonsense. No architect in the 12th century would intentionally build a leaning bell tower for a prestigious cathedral. It would have been a sign of poor craftsmanship and a slight against the Church.
Another one? That Diotisalvi designed it. Diotisalvi was the guy who built the Baptistery nearby. His work is very distinct—lots of geometric precision. While he likely influenced the style, there’s no hard evidence he held the lead role for the tower.
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Why the Design Still Matters
Even with the lean, the architecture is actually incredible. It’s a prime example of Pisan Romanesque style. The tiers of delicate arches, the intricate marble inlay, the way the light hits the white stone against a blue Italian sky—it’s breathtaking.
It reminds us that humans make mistakes. Huge, expensive, multi-century mistakes.
But sometimes those mistakes become more valuable than perfection. If the tower had stayed perfectly straight, it would be just another beautiful Italian bell tower. Instead, it’s a global icon.
What to Do When You Visit
If you're heading to Pisa to see Bonanno’s (and Giovanni’s, and Tommaso’s) work for yourself, don't just take the photo and leave.
- Look for the curve: Walk around the base and look up. You can clearly see where the later architects tried to compensate for the tilt by making the columns longer on one side. It’s a weird, distorted perspective.
- Climb the stairs: There are 294 steps. Because of the lean, you’ll feel yourself being pushed against the wall on one side and then pulled away from it on the other. It’s a disorienting, slightly dizzying experience that really brings the "lean" home.
- Check the Cathedral: Most people ignore the actual Cathedral (the Duomo). Don't. It’s the centerpiece. The tower is just the bell tower for that massive church.
- Visit the Camposanto: The "Holy Field" cemetery on the same grounds has incredible frescoes and Roman sarcophagi. It's much quieter than the tower area.
The story of the Leaning Tower isn't just about a guy with a drawing board. It's a story of soil, ego, war, and 800 years of people refusing to let a building fall down. Whether it was Bonanno Pisano's original vision or John Burland's modern intervention, the tower is a testament to the fact that even when the ground is soft, history can be built to last.
Actionable Insight for Your Trip: Book your climb tickets at least 20-30 days in advance on the official OPAPisa website. Only a limited number of people can be on the staircase at once for structural reasons, and "day-of" tickets are almost non-existent during peak season. Also, remember that you aren't allowed to take any bags—even small purses—up the tower; you’ll have to use the free luggage storage locker near the entrance before you join the queue.