Leaning Tower of Pisa Facts: History and Engineering

leaning tower of pisa factsEvery country has its must-see sights. Italy has countless, but one that every traveler heading to the country knows is the Leaning Tower of Pisa. Don’t let a tour guide or a pamphlet educate you on this historic monument. You can learn all the Leaning Tower of Pisa facts you need in this guide, before you go!

For more tips before your Italian vacation, check out this course on basic travel phrases in Italian, and this guide full of historic, cultural, and geological facts about Italy.

The Leaning Tower of Pisa

The Leaning Tower of Pisa wasn’t always called that. Originally, it was just the Tower of Pisa, or the Torre di Pisa. It name is based on its location in the Pisa province of Tuscany, a district of central Italy known for its vast influence on high Italian culture, the arts and sciences, and also as the place where the Italian Renaissance first got its start.

The tower itself is a campanile, while is a bell tower. The word campanile derives from the word campana, which means “bell.” While it can also be referred to as a belfry, this term is thought of as incorrect because belfries are usually small substructures part of a larger building, such as a church or cathedral, that hold bells. Meanwhile, a campanile specifically means a freestanding bell tower.

The Tower of Pisa got its tilt – and became the Leaning Tower of Pisa – because it was built on soft ground and thus did not have a strong foundation. This actually began during construction of the tower all the way back in 1173, but the tower began to lean further and further for decades as the tower was being built. It was finally stabilized in the 20th and 21st centuries, meaning the tower hopefully won’t completely collapse anytime soon! (If it’s any solace, the tower’s been fine for the past 841 years!)

Looking to take photos of the tower when you’re there? Check out this course on travel photography, and learn more useful photography tips and techniques in this course.

Who built the tower?

Historians can’t say for sure who built the Tower of Pisa. No, this isn’t because the architect was too embarrassed to own up to that now infamous tilt! The records just aren’t exactly clear. In 1820, historians found a piece of cast at the base of the tower with the name Bonanno Pisano written on it. Pisano was an artist and a bronze caster residing in Pisa during the 12th century, and may be the architect of the tower, but historians have also speculated that the cast with Pisano’s name may be part of a bronze door on the tower that was destroyed in 1595.

Another 12th century architect, Diotisalvi, may also be responsible for the tower. However, Diotisalvi was known to sign his works, and because the Tower of Pisa has no such signature, historians remain puzzled by its true architect.

So an architect is one thing, but who actually picked up the tools to build the thing? Diotisalvi is speculated as being part of the tower’s physical construction, especially because he worked on other buildings around Pisa that share similar qualities to the tower. Another builder named Gerardo di Gerardo could have taken part, as well as Giovanni di Simone, who – under the Italian sculptor and architect Giovanni Pisano – helped complete the tower’s construction.

Interested in architecture? Check out this course on model driven architecture, and this one on an introduction to engineering.

Why does the tower lean?

The Tower of Pisa didn’t begin to lean because of a faulty design – at least, not on the part of the actual tower. Rather, the ground it was built on was silty subsoil, an extremely weak foundation that ultimately lead to the tower sinking into the ground – unevenly! The tilt didn’t come in until five years after construction had started, in 1178, when architects began to work on the second floor.

Here’s a fun fact: if the Republic of Pisa hadn’t been at war with Florence, Genoa, and Lucca for nearly an entire century, they would have continued building on the tower before the soil foundation had been allowed to settle. If that had been the case, we surely wouldn’t have the Leaning Tower of Pisa that we have today. In fact, we might not even have it at all – it might have just collapsed completely!

A century later in 1272, construction on the tower continued, but the tilt was still there in full force. The builders actually tried to fix it by engineering the floors on one side taller than the side with the tilt, in an attempt to straighten it out. This didn’t work, but it did give the tower its infamous curve. Construction stopped again and resumed nearly a century later in 1319.

Buildings in the modern era don’t usually take centuries to build. The Tower of Pisa was constructed over a period of 199 years! It’s funny to think about how old the foundation of the tower is compared to its upper floors – it’s a century older, at the least, than the rest of the building. Luckily, a restoration phase between 1990 to 2001 helped strengthen the foundation and touch up the building’s surface.

Technical Facts

If you’re more interested in the engineering than the history of the Leaning Tower of Pisa, here are some technical facts about the actual structure!

  • Height from ground floor: 183 feet, 3 inches – 8 stories / 55.863 metres
  • Height from foundation: 191 feet, 5.64 inches  / 58.36 metres
  • Outer base diameter: 50 feet, 9.6 inches / 15.484 metres
  • Inner base diameter: 24 feet, 2.1 inches / 7.368 metres
  • Slant angle: 3.97 degrees / 12 feet, 10 inches / 3.9 metres from the vertical
  • Elevation of Piazza del Duomo: 6 feet / 2 metres
  • Weight: 16,200 short tons / 14,700 metric tons

In addition to all this, the Leaning Tower of Pisa has a total of seven bells, and 296 steps to the top.

You can learn more about Italian art and architecture in this extensive course on art history from the prehistoric to the Renaissance. Hone in on the Renaissance with this second art history follow-up course. Or, prepare for your Italian vacation with this Italian language learning course.