The road north-west out of Huesca toward Pamplona runs along the foot of a dramatic wall of rock. To the north are the Pre-Pyrenean sierras, and studded along them are some of Aragón's most striking sights: the Castle of Loarre, a superbly preserved Romanesque fortress on a spur, and the Mallos de Riglos, huge red conglomerate towers rising straight out of the hillside. The rock shelter known as the Abrigo de los Gitanos lies in this country, between Ayerbe, Loarre and Luesia.
The name, shelter of the gypsies, is the kind of label locals gave to places where travelling people might camp, and has nothing to do with the prehistoric paintings found there. The art in this part of Aragón tends to be schematic, simple red figures and symbols, and like all the sites in the Mediterranean rock art group it is small, protected and best appreciated with context from a local guide or interpretation centre.
Loarre Castle is the unmissable stop nearby. Built largely in the eleventh century as a frontier fortress during the Christian advance against the Muslim kingdoms, it is one of the best preserved Romanesque castles in Europe, and its walls appeared in the film Kingdom of Heaven. The road up to it from the village winds through pine and holm oak with a superb view over the plain.
For riding, this area is first-class. The A-132 north from Ayerbe toward Murillo de Gállego and Riglos follows the Gállego river past the Mallos, with good bends and dramatic scenery. From there you can carry on toward the reservoir of La Peña and up toward Jaca, or loop west through the quieter Cinco Villas country toward Luesia and Biel, on narrow roads with almost no traffic. Surfaces are mostly good, but watch out for gravel and for cyclists, as the region is popular with them.
Ayerbe has a petrol station and bars, but the nearest town of any size is Jaca, about thirty kilometres away as the crow flies, or Huesca to the south-east. Ayerbe is also known as the place where the Nobel-winning neuroscientist Santiago Ramón y Cajal spent part of his childhood.