Il Ponte della Maddalena is, oddly, also known as the Devil's Bridge. Commissioned in all likelihood by Matilde di Canossa (1046–1115), it was restructured by the petty despot Castruccio Castracani in the early 14th century. It's worth the climb to the middle—the bridge is narrow, steep, and pedestrians-only—to check out the view. Despite 1836 flood damage and early-20th-century alterations, it seems little changed from the Middle Ages. If you're heading north along the Serchio from Lucca to Bagni di Lucca, you will see the bridge on your left.
Bagni di Lucca, Tuscany, Italy