Leaning Tower of Pisa

The Leaning Tower of Pisa, or simply the Tower of Pisa, is the campanile, or freestanding bell tower, of Pisa Cathedral. It is known for its nearly four-degree lean, the result of an unstable foundation. The tower is one of three structures in Pisa's Cathedral Square, which includes the cathedral and Pisa Baptistry. Over time, the flawed tower has become one of the most visited tourist attractions in the world as well as an architectural icon of Italy, receiving over 5 million visitors each year.