The Leaning Tower of Pisa is situated in the city of Pisa, in the Tuscany region of northern Italy, on Piazza dei Miracoli (Square of Miracles). The square’s name was coined by the Italian writer and poet Gabriele D’Annunzio. (In his book *Forse che sì forse che no*, D’Annunzio described this place as a ‘meadow of wonders’.) Piazza dei Miracoli, one of the major centres of medieval European art, is still regarded today as one of the most beautiful architectural complexes, comprising the Pisa Cathedral, the Pisa Baptistery, the Leaning Tower of Pisa (the cathedral’s bell tower) and the Camposanto Monumentale (Monumental Cemetery). It is said that the buildings, displaying a stylistic unity, represent an allegory of human life. The square also houses the Sinopie Museum (Museo delle Sinopie) and the Cathedral Museum (Museo dell’Opera del Duomo).
While the Cathedral of Santa Maria Assunta was being built between 1063 and 1090, construction of its bell tower, the Leaning Tower of Pisa, began on 9 August 1173. Five years after work began, when the building had reached the third floor, construction on the tower was temporarily halted due to the war, as the tower had begun to lean due to a weak foundation. This gave the Tower time for the ground beneath it to settle, and the soil stabilised. Construction resumed around 1270 under the supervision of Giovanni Di Simone. The upper storeys were built with one side higher than the other to compensate for the tilt. Consequently, the tower took on a curved shape. Due to construction being halted again in 1284, the seventh storey was not completed until 1319. The bell chamber was added in 1372. It houses seven bells, one for each note of the musical major scale, and the largest (3.5 tonnes) was cast in 1655.
Measuring 58.36 metres in height from ground level, the Tower has an inclination of approximately 5° and an external diameter of 15 metres. It is accessed via a total of 273 steps. The total weight of the Tower is 14,453 tonnes. The structure of the Leaning Tower of Pisa consists of two chambers. One is located at the base of the tower. Known as the Fish Room due to a relief depicting a fish, this chamber has no ceiling. The other is the bell chamber located on the eighth ring. This section is also open to the sky, and as a result, it is possible to see the lower storey of the tower through an opening in the centre. Furthermore, there are three staircases within the building. The first runs continuously from the base to the sixth ring. The second is a smaller spiral leading from the sixth to the seventh ring. Finally, there is another spiral staircase extending from the seventh ring to the top.
The world-famous Tower underwent its first restoration between 1910 and 1920. Cement was injected beneath its foundations. The building was closed for a period during another restoration between 1990 and 2001. On this occasion, corrective reconstruction and stabilisation work was carried out on the Tower. The aim was to halt the tilt by placing weights on the northern side of the foundation, and this proved successful. The Tower was declared stable for at least another 200–300 years. In May 2008, instruments installed in the structure showed that the Tower had ceased moving entirely. On 22 April 2011, restoration work on both the internal and external stone surfaces of the structure was completed. Soil analyses conducted during the restoration revealed the presence of significant amounts of groundwater causing the ground to subside; to resolve this issue, large quantities of water were pumped out from underground. However, this action encouraged the subsidence, and consequently, the tower’s tilt increased. The tower has withstood at least four powerful earthquakes since 1280. Following an engineering assessment in 2018, it was concluded that the tower withstands tremors due to dynamic soil-structure interaction. The same soft soil that caused the tilt and brought the tower to the brink of collapse had, on this occasion, helped prevent significant damage in the event of an earthquake. A ceremony was held on 9 August 2023 to mark the 850th anniversary of the laying of the foundation stone.
The identity of the tower’s architect remains a subject of debate. The Leaning Tower of Pisa, believed to have been built by Bonnano Pisano or Diotisalvi, was inscribed on the UNESCO World Heritage List in 1987. It is said that between 1589 and 1592, Galileo Galilei, who was living in Pisa at the time, observed that all objects fall at the same speed and in accordance with the same laws of physics by dropping two cannonballs of different weights from this tower. Although the source of this information is said to be one of Galileo’s students, the experiment is generally regarded as a myth.
Part of the Piazza del Duomo complex, the Leaning Tower of Pisa boasts a truly awe-inspiring appearance. It is world-famous both for its location within this complex and for its unique tilt, which transforms it into a true static marvel. Commonly known as the Leaning Tower, this bell tower is one of Italy’s iconic symbols. It is among the world’s most visited architectural structures and welcomes millions of visitors every year.