The Torre di Pisa, or Leaning Tower of Pisa, is a freestanding bell tower located in Pisa, Italy. It is famous for its unintended tilt, which began during its construction in the 12th century due to unstable foundation soil. The tower stands approximately 56 meters tall and has eight stories, including the chamber for the bells. Constructed primarily of white and gray marble, the Torre di Pisa showcases Romanesque architecture. It is part of the Piazza dei Miracoli, a UNESCO World Heritage Site that also includes the Pisa Cathedral and the Baptistery. The tower attracts millions of visitors each year.