Oviedo may be the political center of the Principality of Asturias, but Covadonga is its spiritual heart. This mountain sanctuary near Cangas de Onís is where King Pelayo led a ragtag bunch of Christians to victory over a much larger Muslim force in the 8th century. It was Christianity's first triumph since the Moorish conquest of Iberia, and marked the beginning of the 800-year Reconquista.
The Way of Saint James, or the Camino de Santiago as it's called in Spain, is one of the oldest and most famous Christian pilgrimages, probably right behind Jerusalem. Ending in Santiago de Compostela and starting from any number of spots, though usually in France, the pilgrimage requires a commitment of months.