Mequinenza sits where the Segre and the Cinca join the Ebro, and the Barranco de la Plana, a dry gully less than a kilometre from the town, is one of the painted shelters scattered through the hills above them. The ride that includes it also touches Roca Roja, the Red Rock, and another shelter of the Abrics d'Ermites group far to the south, which shows how far these rock-art routes range. The paintings belong to the Levantine tradition, protected by UNESCO along with the rest of the Mediterranean rock art of Spain, and in this semi-arid corner of Aragón, where there is little to shelter a painted wall from the weather, what survives is a small miracle.
The land around has been rewritten twice in living memory. First came coal: lignite was mined in the hills around Mequinenza, and for decades it was loaded on barges and floated down the Ebro. Then came the dam at Ribarroja, in the 1960s, whose reservoir drowned the old town and forced its families uphill into a new one. The town's best-known writer, Jesús Moncada, made that lost world the subject of his novels, and if you want to feel what the place was like, his name is the one to look for in a bookshop. The reservoir, the Mar de Aragón, now fills the valley with a long ribbon of blue-green water, an odd and rather beautiful sight in a landscape of pale rock and thyme.
Fish are the draw for many visitors, and the catfish of the Ebro are famous among anglers. For riders, the draw is the road. It twists above the water, with long sightlines and few cars, and it passes through a country that looks more like North Africa than the green Spain of postcards. The tarmac is good, and the bends are well cambered. Wind is common, especially in the afternoon, and the sun is strong enough to make a visor tint a good idea in every season but winter.
Mequinenza has about two and a half thousand people and enough services for fuel and a meal. Fraga, about sixteen kilometres away, is bigger, with more than fourteen thousand people, and has everything. Seròs and Fayón, on the Catalan and Aragonese sides of the border, are small but useful for a coffee and a rest on the way.