Covacho is the Aragonese word for a small cave or overhang, and Palluala is one of the hillside patches near Alquézar that carry the old farming names of the valley. The shelter, a mere kilometre and a bit from the village, is probably the nearest to it of all the painted rocks on this list, which means you can leave the motorbike in the village and walk instead of making a project of it. As with its neighbours it belongs to the Levantine rock art of the Spanish Mediterranean, listed by UNESCO in 1998.
Alquézar is where the day should be spent. It lies on a spur of rock above a bend in the Vero, a huddle of stone houses with brown tiles around the collegiate church, which was built on the site of a Muslim fortress, and which the Aragonese king took in the eleventh century. A series of wooden walkways, the pasarelas, hang from the cliff on the far side of the village and lead you in a loop above the river and down to a viewpoint. Allow two hours and take a hat. It gets very hot in the narrow part of the gorge.
The ride from Barbastro up the A-1232 has a quality that many riders overlook, because it is not especially fast. It twists, drops and rises through a landscape of oak, almond and scrub, with the Sierra de Guara looming larger at each bend. In spring the fields are bright with poppies and the stream is full. In summer the villages are busy with weekenders and in winter many bars close, so check opening before you plan a long lunch.
Because Alquézar has only about three hundred residents, the pumps are down in Barbastro, nineteen kilometres away. The town is the commercial heart of the district, with a late Gothic cathedral, a market and a long tradition of wine making, and it is a good place to buy bread, cheese and cured meat for a picnic before heading up the valley. Bring water for the shelter, and remember that the paintings cannot be touched.