Above the village of San Felices de Buelna, on a limestone hillside in the Besaya valley of Cantabria, a cave called Hornos de la Peña holds engravings made by Palaeolithic hunters. The most famous is the outline of a horse, scratched into the rock thousands of years ago, along with other animals and signs that take time and a good guide to pick out. The cave is one of the seventeen in northern Spain listed by UNESCO alongside Altamira, and visits are limited and guided, so check ahead rather than simply turning up.
This part of Cantabria is a crumpled green landscape of meadows, chestnut woods and limestone crags, with the river Besaya running north to the sea at Torrelavega. Los Corrales de Buelna, the town just below, grew around steel and wire works and is a practical, unpretentious place with fuel, shops and bars. A few kilometres east, at Puente Viesgo, Monte Castillo hides another cluster of decorated caves, including El Castillo itself, where some of the hand stencils on the walls have been dated among the oldest cave art in Europe. Together they make a remarkable half day.
The riding around here is very good and very green. Small roads climb out of the Besaya and the Pas valleys into rolling uplands, with tight bends through villages and longer flowing sections across open pasture. The Pas valley, east of Puente Viesgo, is home to the pasiegos, a pastoral people with a strong identity who moved their cattle between scattered stone cabins on the hillsides. The road up to the passes at the head of the valley is a favourite, steep and twisting, with views over a landscape that looks almost alpine. Expect cows on the road and wet tarmac in shaded corners.
Rain is part of the deal. Cantabria is green because it gets weather from the Atlantic all year, and fog sits in the valleys on many mornings. When the sun comes out, though, the colours are intense, and the light after a shower is beautiful. Summer is the driest season and the busiest.
Do not leave without trying the local sweets. Sobaos pasiegos, dense buttery sponge cakes, and quesada, a baked cheese pudding, are the pride of the Pas valley and are sold in every bakery and petrol station shop. Pair them with coffee in Puente Viesgo before the next climb.