In 1997, in a cave that people had been visiting for over a century, a group of researchers noticed paintings that everyone had walked past: a frieze of red figures, deer, horses and goats, high on a wall in the main chamber. El Pendo, in the municipality of Camargo just south of Santander, had long been known for its deep layers of Stone Age occupation, but the frieze made it one of the important painted caves of Cantabria, and in 2008 it joined the World Heritage listing of the Paleolithic cave art of northern Spain alongside Altamira.
The cave opens at the foot of a wooded slope in a little valley, surprisingly close to the suburbs of the Santander bay. Visits are guided and limited in number to protect the art, so booking ahead is wise, especially in summer. Inside, the main chamber is huge, cool and damp, and the guides show the paintings with careful lighting.
Cantabria is green because it rains, and the weather turns quickly off the Bay of Biscay. On a bike, that means wet roads under trees, moss in the gutters and cow muck on rural lanes, but it also means lush valleys, limestone peaks and empty mountain roads just behind the coast. From Camargo, you can head south to the valleys of the Pas, home of the pasiegos, the herding families who move their cattle between stone huts on the slopes, and climb roads like the Puerto de la Braguía or the Puerto de las Estacas de Trueba, both twisting and steep with superb views. The sobaos and quesadas pasiegas, buttery sponge cakes and a set cheesecake, are local specialities sold in every village.
Camargo is a busy town of over thirty thousand, effectively part of greater Santander, with all the fuel, food and services you need. Santander itself has a handsome bay, beaches and the Magdalena palace on its peninsula. Peña Cabarga, a mountain topped with a monument east of the bay, has a road to its summit that gives a sweeping view over the whole area on a clear day. Rush hour around Santander is heavy, so time your ride to avoid it.