5 Best Sights in Galicia and Asturias, Spain

These world-famous caves, 3 km (2 miles) southwest of Santillana del Mar, have been called the Sistine Chapel of prehistoric art for the beauty of their drawings, believed to be some 18,000 years old. First uncovered in 1875, the caves are a testament to early mankind's admiration of beauty and surprising technical skill in representing it, especially in the use of rock forms to accentuate perspective.   Only 5 visitors are allowed into the caves each week, and entrance is determined by a lengthy waiting list. The reproduction in the museum, however, is open to all.

Santillana del Mar is built around the Colegiata, Cantabria's finest Romanesque structure. Highlights include the 12th-century cloister, famed for its sculpted capitals, a 16th-century altarpiece, and the tomb of Santa Juliana, who is the town's patron saint and namesake.

Inside the 16th-century Regina Coeli convent is a museum devoted to liturgical art, which includes wooden figures of saints, oil paintings of biblical scenes, altarpieces, and a collection of sacred treasures from the colonial New World.

Inside the 16th-century Regina Coeli convent is a museum devoted to liturgical art including wooden figures of saints, oil paintings of biblical scenes, altarpieces, and a collection of plundered treasures from the so-called New World.

In 1903, four caves were discovered in this 16th-century hamlet in the Pas Valley, under the 1,150-foot peak of Monte del Castillo. Two of these—Cueva del Castillo and Cueva de las Monedas—are open to the public. Bison, deer, bulls, and humanoid stick figures are depicted within the caves; the oldest designs are thought to be 35,000 years old. Most arresting are the paintings of 44 hands (35 of them remain). The painters are thought to have blown red pigment around their hands through a hollow bone, leaving the negative image. Online reservations are essential.