The Nansa is one of the shortest and wildest rivers in Cantabria, running from the high mountains on the edge of the Picos de Europa to the Bay of Biscay, and halfway along its course, near the hamlet of Riclones, a cave opens in the limestone above the water. This is the Cueva de Chufín, where Palaeolithic people engraved and painted animals, signs and symbols on the walls thousands of years ago. It is one of the caves of the Cantabrian coast included in the World Heritage site of Altamira and Palaeolithic cave art of northern Spain.
The cave is small and the art is subtle: engravings of deer, horses and bison, and enigmatic signs in red pigment. What makes Chufín special is the setting. The entrance looks out over the river and the steep, forested slopes of the valley, and the approach is beautiful. Visits are limited, so check ahead if you hope to see inside.
The riding in the Nansa valley is superb. The road from San Vicente de la Barquera on the coast climbs up the valley through Puentenansa, following the river through gorges and green meadows, with tight bends and steep climbs. Further up, the road continues towards the Puerto de Piedrasluengas, a mountain pass with views over the Picos de Europa and the high plateau of Palencia. The surface is generally good, but watch for livestock, gravel and wet patches. Cantabria is green for a reason: rain is frequent, even in summer, so bring good gear.
The valley is a classic example of the green Spain of the north, with hay meadows, stone farmhouses, chestnut and oak woods, and cows grazing on steep slopes. Vultures circle overhead, and the river is home to salmon and trout. The villages are small and traditional, with stone houses and wooden balconies, and the people are known for their hospitality.
San Vicente de la Barquera, about eleven kilometres away, is a fishing town with a castle, a Gothic church and a long bridge across the estuary, and it has fuel, restaurants and accommodation. Cabezón de la Sal and Comillas, with its modernist buildings including a villa by Gaudí, are also nearby. Try cocido montañés, a hearty bean and cabbage stew, or sorropotún, a tuna and potato dish from the coast.