Alquézar
"Alquézar doesn't sit on the cliff so much as grow out of it, stone matching stone until you can't say where the mountain ends."
A cluster of stone houses clings to a limestone cliff above the Río Vero gorge, guarded by a fortress the Moors built to watch the canyon below.
The first view of Alquézar is the kind that makes you pull the car onto the shoulder even when there’s nowhere safe to stop. You come around a bend on the road from Barbastro and the whole village appears across the gorge — ochre stone houses stacked up a cliff face, a collegiate church crowning the top, the Río Vero cutting a pale green ribbon through limestone walls a hundred meters below. The name itself gives away its origin: from the Arabic al-qasr, “the castle.” The Moors built a fortress here in the ninth century specifically because the cliffs did half the defensive work for them, and the town that eventually grew inside its walls never really left the shape that decision gave it.
Walking the Passarelles
What pulls most visitors to Alquézar today isn’t the history so much as the canyon itself. The Río Vero has carved a network of narrow limestone gorges through the Sierra de Guara, and a via ferrata-adjacent walkway called the Pasarelas del Río Vero threads along the cliff face just above the water — a mix of carved rock steps, iron railings, and suspended metal walkways bolted directly into the canyon wall. I did the loop in early morning before the day-trippers arrived from Huesca, and for long stretches the only sound was the river below and the occasional griffon vulture riding the thermals overhead — the Sierra de Guara is one of the densest vulture nesting areas in Europe, and you feel their presence before you spot them, this slow rotation of shadows on the canyon walls.
The gorge itself has been used by humans for tens of thousands of years — there are prehistoric rock art sites scattered through the Sierra de Guara, some dating back over 20,000 years, though the more accessible cave paintings require a guide to visit responsibly. Even without seeking those out, walking the canyon floor with walls rising sheer on both sides gives you a sense of why people kept coming back to this particular cut in the rock.

A Collegiate Church Standing Guard
Back up in the village, the Colegiata de Santa María la Mayor occupies the site of the old Moorish fortress’s mosque, rebuilt over centuries into a Gothic-Romanesque hybrid with a cloister whose capitals are carved with scenes I kept circling back to try to fully decode — biblical narratives tangled with what look like local folk motifs. From the church’s terrace the whole gorge opens up beneath you, and I stood there at sunset watching swifts cut low over the rooftops while the stone of the houses went the same burnt orange as the cliff they’re built on. Alquézar has fewer than three hundred permanent residents now, and in the evening, once the hiking groups clear out, that smallness becomes obvious — a few lit windows, the smell of woodsmoke, the river still audible somewhere below.

When to go: Late spring (May) or early autumn (September–October) give you canyon-walking weather without the summer heat that turns the gorge trails into an oven by midday.