Designated a World Heritage Site by UNESCO, together with the whole of Pisa's Piazza del Duomo, the tower is a fundamental example of the Romanesque style, in particular Pisan Romanesque, and a fine example of medieval engineering.
The Tower of Pisa, one of the most admired and famous buildings in the world, has begun its 850th birthday celebrations after the laying of its first stone on 9 August 1173.
Considered a World Heritage Site by UNESCO, together with the whole of Pisa's Piazza del Duomo, the tower is a fundamental example of the Romanesque style, in particular Pisan Romanesque, and a fine example of medieval engineering as it has remained leaning from the beginning of its construction due to the instability of the ground.
The city has arranged a programme that will last until 9 August 2024, which includes an exhibition featuring the paintings, engravings, photographs and films that have immortalised the work over the years - 'The Many Lives of the Pisa Bell Tower'.
Symphonic music concerts and film screenings will also be organised in the cycle "Il Cinema e la torre".
Although the Leaning Tower of Pisa is now stable, this was not always the case.
In the 1990s, the Italian authorities had to close the bell tower to the public and launched a competition for ideas to reinforce its structure and prevent it from collapsing, as the situation was critical.
The first intervention, which consisted of adding lead counterweights to the structure, did not solve the problem, so it was finally decided to excavate the earth to reduce the slope of the tower and ensure its preservation.
"The rescue of the bell tower allows us to celebrate the 850th anniversary and to appreciate the efforts of our ancestors in the arrangement of the monuments in the Duomo square," the president of the Opera Primaziale, the monument's managing body, Andrea Maestrelli, told the local press.