Museum Estación de Arte Rupestre de Siega Verde in Villar de la Yegua

You're standing at Siega Verde, on the banks of the Águeda river, close to the hamlet of Serranillo. There's no art hanging on a gallery wall here. The art is right in the rocks along the water, out in the open air. That's exactly what makes this place special. Most prehistoric art in Europe is hidden deep inside caves. Open-air sites like this one are far rarer.