50 Fun Facts About Leaning Tower of Pisa

The Leaning Tower of Pisa was built to serve what function?

It is a freestanding campanile, one of three structures in the Cathedral Square alongside the cathedral and baptistery.

Pisa is a city in which region of Italy?

It straddles the Arno just before the river reaches the Ligurian Sea.

Why did the tower begin to lean during construction?

Its foundation was a mere three metres deep, set in weak subsoil, a design flawed from the beginning.

Roughly how tall is the tower on its low side?

It measures 55.86 m on the low side and 56.67 m on the high side, and weighs about 14,500 tonnes.

After stabilisation work ended in 2001, what was the tower's angle of lean?

It had reached 5.5 degrees by 1990; the correction pulled it back 45 centimetres to its 1838 position.

Construction of the tower took place in three stages over how many years?

Work began in 1173 and the bell chamber was finally added in 1372.

The first stones of the tower were paid for by a bequest of sixty soldi from whom in 1172?

Her small legacy bought stones that still form the base of the campanile.

Construction halted for most of a century after the tower started sinking in 1178. What ultimately saved it from toppling?

Pisa was busy fighting Genoa, Lucca and Florence, and the long pause let the subsoil compact under the half-built tower.

To compensate for the tilt, builders in the 1270s made the upper floors taller on one side. What is the visible result?

Master builder Giovanni di Simone, architect of the Camposanto, resumed the work in 1272.

Work stopped again in 1278 after Pisa's fleet was defeated at the Battle of Meloria by which rival republic?

The 1284 defeat began Pisa's decline as a maritime power.

How many bells hang in the tower's belfry, completed in 1372?

There is one for each note of the major scale; the largest, L'Assunta, was cast in 1654.

The bell called La Pasquareccia originally hung elsewhere in Pisa and was tolled to announce what?

Once known as La Giustizia, it rang for the death of Count Ugolino in 1289 and predates the belfry itself.

Which scientist, then living in Pisa, is said to have dropped two cannonballs from the tower to show that objects fall at the same rate?

Most historians think it was a thought experiment; the only source is a biography by his pupil Vincenzo Viviani.

The story of Galileo's tower experiment comes from a biography written by his pupil and secretary. Who was he?

He wrote it in 1654 but it was not published until 1717; the same premise had been demonstrated in Delft by Simon Stevin decades earlier.

During the Second World War, US Army sergeant Leon Weckstein was sent to check whether the tower was being used as a German observation post. What did he do?

Struck by the beauty of the cathedral and its campanile, he could not bring himself to give the order.

Starting in 1993, how much lead counterweight was stacked on the tower's raised side?

The lead straightened it slightly while engineers prepared the soil-extraction fix.

The tower was closed to the public in January 1990, spurred partly by the sudden collapse of a tower in which Italian city the year before?

The bells were removed, cables anchored around the third level and homes in the potential fall zone were evacuated.

The method finally chosen to save the tower was to do what?

Around 38 cubic metres of soil were extracted, reducing the tilt by 45 centimetres, and Italy wanted the lean kept for tourism.

When the tower reopened on 15 December 2001, engineers declared it stable for at least how long?

In 2008 they announced it had stopped moving for the first time in its history.

Which British engineer was asked by the Italian government in 1990 to join the 14-member committee that stabilised the tower?

He became the public face of the soil-extraction work in the 1990s.

A 2018 study found the tower has survived at least four strong earthquakes since 1280 because of what?

The same soft soil that made it lean stops it resonating with earthquake ground motion.

The tower, cathedral, baptistery and cemetery were declared a UNESCO World Heritage Site in which year?

The square is officially the Piazza del Duomo, though everyone calls it the Piazza dei Miracoli.

The square's nickname Piazza dei Miracoli, 'meadow of miracles', was coined by which Italian writer in a 1910 novel?

He called it the 'prato dei Miracoli' in Forse che sì forse che no.

The Camposanto, the cemetery beside the tower, is said to have been built around a shipload of soil brought from where?

Archbishop Ubaldo Lanfranchi supposedly shipped it back from the Third Crusade in the 12th century.

What happened to the Camposanto on 27 July 1944?

The fire burned for three days, collapsing the lead roof and ruining most of the frescoes and sarcophagi.

Construction of Pisa Cathedral began in 1064 and was funded how?

Granite columns looted from the mosque of Palermo still stand between its nave and apse.

A lamp in the cathedral's nave is called Galileo's lamp because of a legend that watching it swing led him to which discovery?

The original lamp, smaller and different, is now in the Camposanto.

The round building begun in 1152 to house the cathedral's font holds what distinction?

A 2001 study suggests its architect Diotisalvi may also have designed the leaning tower.

A 2001 study suggested the tower's original architect was Diotisalvi rather than which artist long credited with it?

A piece of cast bearing Bonanno's name was found at the tower's foot in 1820, but it may belong to a cathedral door destroyed in 1595.

Roughly how many steps lead to the top of the tower?

Sources give 296 or 294, because the seventh floor has two fewer steps on the north-facing staircase.

Roughly how many visitors does the tower receive each year?

Italy insisted the lean be preserved during the rescue because of its value to tourism.

A German church steeple in Suurhusen has challenged Pisa's title as the world's most tilted unintentionally leaning tower. In which region is it?

As of 2007 it claimed a lean 1.22 degrees greater than Pisa's; the Oberkirche at Bad Frankenhausen is another challenger.

In 2010 Guinness World Records certified which building as the world's furthest-leaning man-made tower, with an 18-degree slope?

It was deliberately engineered to slant, almost five times more than Pisa.

A deliberately built Leaning Tower in Wānaka, New Zealand, leans at what angle to the ground?

It stands in the Puzzling World attraction.

Pisa was the birthplace of which scientist, born there in 1564?

Fibonacci, the medieval mathematician, was also from Pisa but two centuries earlier.

The University of Pisa, where Galileo later taught mathematics, was founded in which year?

Its presence gave the city a mainly cultural role after its maritime power faded.

The walls at the tower's base are how thick?

They support an estimated 14,500 tonnes of marble.

The 850th anniversary of the laying of the tower's foundation stone was marked with a ceremony on 9 August of which year?

The foundations were laid on 9 August 1173, and the ground floor began five days later.

The tower's belfry incorporates a correction of how much for the inclined axis beneath it?

Tommaso di Andrea Pisano built the Gothic belfry in 1372 to sit on the Romanesque tower below.

In which year did the Italian government first formally request international aid to keep the tower from toppling?

It stipulated that the tilt itself must be preserved because of its importance to Pisa's tourism.

The 12th-century artist long credited with the tower is best known for casting the cathedral's Porta Reale in what material?

He cast the Porta Reale of Pisa Cathedral, destroyed by fire in 1595, and left for Monreale in Sicily in the 1180s.

The tower's tilt had reached what angle by 1990, prompting its closure?

Its centre of gravity had drifted about 3.9 metres from the vertical.

How much soil was removed from beneath the tower's raised end during the 1990s stabilisation?

It reduced the tilt by 45 cm, returning the tower to its 1838 position; 70 tonnes of soil were taken out in all.

Roughly how much does the Leaning Tower weigh?

Its foundation was a mere three metres deep, set in weak subsoil.

Which master builder, also architect of the Camposanto, resumed work on the tower in 1272?

His engineers built the upper floors taller on one side to compensate for the tilt, curving the tower.

Which of the tower's seven bells is the heaviest, at 3,620 kg?

It was cast in 1654 by Giovanni Pietro Orlandi; the bells are tuned to the notes of a major scale.

In May 2008 engineers announced what about the tower for the first time in its history?

They declared it stable for at least 200 years; surface restoration of corrosion and blackening continues.

Pisa straddles which river just before it empties into the Ligurian Sea?

The city's name is thought to come from an Etruscan word meaning 'mouth'.

Who founded Pisa's Scuola Normale Superiore in 1810?

Its offshoot, the Sant'Anna School of Advanced Studies, is also in the city.

How large is the walled Piazza dei Miracoli compound?

The whole complex was owned by the Catholic Church.