The Leaning Tower of Pisa stands in the Italian city of Pisa, in Tuscany. It is the freestanding bell tower, or campanile, of Pisa Cathedral.
Construction began in 1173 in the Piazza del Duomo, the cathedral complex also known as the Piazza dei Miracoli, or Square of Miracles. The tower began leaning during construction because it was built on soft, unstable subsoil with a shallow foundation. Work was interrupted for long periods by wars, allowing the ground to settle and probably preventing the tower from collapsing.
The tower was built in stages over nearly two centuries. Its bell chamber was added in 1372, and the completed structure has eight levels and seven bells. The lean became dramatically worse over time, reaching about 5.5 degrees before modern stabilization work reduced it to roughly 3.97 degrees.
A common mix-up is to answer Florence because Florence is Tuscany’s regional capital and a major Italian tourist city. Pisa, however, is its own historic city on the Arno River, near the Ligurian Sea. The tower, cathedral, baptistery, and monumental cemetery together form a UNESCO World Heritage Site.