3 Best Sights in Brittany, France

Built by the Nazis during World War II, this submarine base is the world's largest 20th-century fort. Thirty submarines could be comfortably housed in the squat concrete bunker—and its 27-foot-thick roof withstood intensive Allied bombing virtually intact. Ninety-minute tours begin at noon and 3 pm daily in summer and during school vacations; they run at the same time on Sunday year-round. Call to find out when tours in English are scheduled.

Held in the first half of August, this festival focuses on Celtic culture—music, drama, poetry, dance—and fellow Celts from Cornwall, Wales, Ireland, Scotland, Galicia, and other Western European locales pour in to celebrate.

There's a good beach, Larmor-Plage, 5 km (3 miles) south of Lorient. You can also take a ferry to the rocky yet utterly charming Île de Groix or cross the bay to Port-Louis to see its 17th-century fort and ramparts.