Pisa is a commune in Tuscany, central Italy. It lies on the alluvial plain of the Arno River, about 10 km from the Ligurian Sea and 80 km west of Florence. Pisa lay by the sea until the 15th century, by which time accumulated silt deposited by the Arno River had completely cut the city off from the receding shoreline.
Pisa is now a quiet provincial university town that is renowned for its art and architectural treasures. The city also retains much of its 10.5 km circuit of walls. Pisa is distinguished above all by a remarkable group of buildings in the Piazza del Duomo, the so-called Square of Miracles, located at the northwestern end of the medieval walled city. This piazza contains the cathedral, or Duomo; the baptistery; the campanile, or Leaning Tower of Pisa; and the camposanto, or cemetery.