8 Best Sights in The Basque Country, Gascony, and Hautes-Pyrenees, France

Lourdes celebrated the centenary of Bernadette Soubirous's visions by building the world's largest underground church, the Basilique Souterraine St-Pie X, with space for 20,000 people—more than the town's permanent population. The Basilique Supérieure (1871), tall and white, hulks nearby.

Built mainly in the 13th century, the Cathédrale (called both Ste-Marie and Notre-Dame) is one of France's southernmost examples of Gothic architecture. Its 13th- to 14th-century cloisters are among its best features.

Eugénie and her Carlist compatriots weren’t the only exiled royals to arrive in Biarritz. White Russians found refuge, too, turning the city into their Yalta-by-the-Atlantic. Witness the Église Orthodoxe Russe, a Byzantine-style church they built adjacent to the Grand Plage in the early 1890s. Note that opening hours can be irregular.

One of the Labourd province's prettiest churches was built in the 16th century and enlarged in the 17th with a triple-decker set of galleries. Parish priest Pierre Axular ranks among the great early authors in the Basque language. His tomb is under the bell tower with an epitaph by Prince Bonaparte: "Every hour wounds; the last sends you to your tomb."

The marriage of the Sun King and the Infanta took place in 1660 in the church of St-Jean-Baptiste. The marriage tied the knot, so to speak, on the Pyrénées Treaty signed by French chief minister Mazarin on November 7, 1659, ending Spanish hegemony in Europe. Note the church's unusual wooden galleries lining the walls, creating a theaterlike effect. Fittingly, St-Jean-Baptiste hosts a "Musique en Côte Basque" festival of early and Baroque music during the first two weeks of September.

If you wish to pay your respects to the Empress Eugénie, visit La Chapelle Impériale, which she had built in 1864 to venerate a figure of a Mexican Black Virgin from Guadalupe (and perhaps to expiate her sins for furthering her husband's tragic folly of putting Emperor Maximilian and Empress Carlotta on the "throne" of Mexico). The style is a charming hybrid of Roman-Byzantine and Hispano-Mauresque. Entry is by guided tour only, and open days and hours are changeable, so call ahead.

Walk into the old section of St-Jean-Pied-de-Port through the Porte de France, just behind and to the left of the tourist office; climb the steps on the left up to the walkway circling the ramparts; and stroll around to the stone stairway down to the Rue de l'Église. The church of Our Lady of the End of the Bridge, known for its magnificent Gothic Rayonnant doorway, is at the bottom of this cobbled street. Built in the 12th century and designated a church in the 13th century, it is a characteristically Basque three-tier structure.