Hoces del Rio Riaza

The Riaza has cut a canyon through red and ochre limestone on the northern edge of Segovia province, and in 1975 the World Wildlife Fund established a refuge here to protect the griffon vultures nesting on its walls; from around twenty pairs then the colony has grown into several hundred, one of the densest concentrations in Europe, alongside Egyptian vultures, golden eagles, peregrines and eagle owls. The reserve is one of the longest continuously monitored raptor sites in the world, with feeding and census work running since the 1970s. Viewpoints along the canyon rim give sightings without entering the protected zone, and guided visits to the refuge itself are arranged through the managing organisation.

What you actually see

• The vulture colony - several hundred griffon pairs on the canyon walls.
• The red limestone - ochre and rust-coloured rock through the gorge.
• The rim viewpoints - overlooks giving sightings from outside the reserve.
• The reservoir - the Linares del Arroyo dam at the canyon's edge.

When to go

April to June for birds at the nest with chicks, September and October for autumn light and clear air; access to parts of the reserve is restricted during the breeding season to prevent disturbance.

Honest expectations

The core refuge is closed to casual visitors and needs a booked guided trip. Viewpoints are at a distance and binoculars are essential. The area is remote with limited facilities, and disturbance rules are enforced.

Nearby

Maderuelo and the Linares reservoir are alongside; Aranda de Duero lies north.