The road across northern Spain to Santiago de Compostela in the northwest was one of the three major Christian pilgrimage routes during the Middle Ages, leading pilgrims to the resting place of the Apostle St. James. Today, the system of trails and roads that made up the old pilgrimage route is the most popular long-distance trail in Europe, winding from the heights of the Pyrenees to the gently rolling fields and woods of Galicia. Hundreds of thousands of modern-day pilgrims, art lovers, historians, and adventurers retrace the road today, traveling through a stunningly varied landscape...