The Río Martín is a modest river by Spanish standards, but it has carved one of the most interesting canyons in Aragon, and the Cultural Park that takes its name protects an extraordinary collection of rock art. El Cerrao is one of the shelters in that park, in the district of Montalbán in the province of Teruel, among cliffs of pale limestone above a dry valley. The paintings here belong to the Levantine tradition and are part of the group UNESCO inscribed in 1998.
Montalbán is a handsome small town of fewer than fifteen hundred people, with a medieval church and the ruins of a castle that once belonged to the Order of Santiago. The country around is called the Bajo Aragón, a landscape of olive terraces, almond trees, cereals and sparse pine, scattered with villages whose names, like Alcaine, Ariño and Albalate del Arzobispo, tell you something of the region's Moorish and ecclesiastical history. Coal mining shaped Ariño and nearby Andorra, and the old workings still scar the hills.
Further east is Calanda, the birthplace of the film director Luis Buñuel, and the home of a Holy Week tradition in which thousands of drummers fill the streets at the same moment, a sound that is exciting and a little overwhelming. If you are in the region at Easter, you will hear it for miles.
On the road the pleasure is solitude. Routes through the Río Martín valley are lightly used, with open bends, long views and good surfaces on the main roads. In summer the heat is fierce and the shade scarce, and in winter the cold can be sharp, with fog collecting in the valleys. Spring and autumn are the easy seasons, and the light on the limestone is beautiful.
Fuel is available in Andorra, a town of nearly eight thousand people about twenty-six kilometres away, and Montalbán may have a pump, though it is wise not to rely on it. Carry water, because the shelters are dry and exposed.