Next to Chiesa di Sant'Agostino, a steep path known as Via della Rocca leads up to the remnants of Pietrasanta's ancient fortifications. The crenellated city walls date from the early 1300s and what remains of Palazzo Guinigi was built as a residence for the signore of Lucca, Paolo Guinigi, in 1408. Views of the city and the deep-blue Mediterranean beyond are worth the short climb.