town, centre of a district known as Versilia, Toscana ( Tuscany) regione, central Italy, at the foot of the Alpi Apuane (mountains) just southeast of Carrara. Its piazza is surrounded by fine buildings including the Cathedral of San Martino and the Church of San Agostino (a baptistery with a medieval font), both dating from the 14th century, and the remains of the Rocca, a 12th-century citadel. Pietrasanta was strategically situated on the German Gothic Line in World War II and saw heavy fighting. Agricultural activities, tourism, and the quarrying and processing of marble are its principal industries. Pop. (2006 est.) mun., 24,630.