概要
The Leaning Tower of Pisa is the freestanding bell tower (campanile) of Pisa Cathedral in the Piazza del Duomo (Campo dei Miracoli), Tuscany, Italy. Construction began in 1173; by the time workers reached the third storey the tower had begun to tilt on unstable alluvial soil. Work stopped and resumed across centuries; the cylindrical structure of white marble wraps eight storeys with a spiral staircase of 294 steps.
The lean reached more than 5 degrees before 20th–21st-century stabilization injected soil and adjusted mass, reducing tilt to safer levels while preserving the signature angle tourists expect. Ghiberti and other Renaissance masters referenced Pisa's marble ensemble as a benchmark of Tuscan Romanesque.
The tower is not separate from the cathedral complex UNESCO inscribed in 1987 — it is the most photographed element. Climbing the tilted stairs remains a bucket-list ritual; the view encompasses the Arno plain and Tuscan coast.