From Gistaín Aínsa - Revilla Itinerary
Starting point: Aínsa.
Time: About half a day.
Head to the beautifully restored medieval quarters of Aínsa, worth a visit in themselves. From the walls a number of large raptors can usually be seen, including Griffon Vulture, Red Kite, Black Kite, Egyptian Vulture and Booted Eagle. With the help of a telescope it may also be possible to see Lammergeier and Short-toed Eagle. In the evenings European Nightjars can be heard or even seen hawking insects around the town lights.
After a quick look at the river for Little Ringed Plover, Dipper and Grey Wagtail take the road to Bielsa. Between here and Escalona roadside birds include Cirl Bunting, Quail, Spotless Starling, Serin, Green Woodpecker and Short-toed Treecreeper. Nevertheless, at any point along this road it is always worth keeping one eye on the sky as the number and variety of raptors here is exceptional.
On arrival at Escalona a decision needs to be taken: the unique ambience of the Añisclo gorge (can get busy during holiday periods!), a walk into the park from the tiny village of Escuaín, or the viewpoint of Revilla overlooking the Escuaín gorge and the place where the best views of Lammergeier can often be had.
If choosing one of the first two options then take the next turning on the left at the exit from Escalona. By following the same road you will reach the Añisclo gorge, while to go to Escuaín you need to turn off to the right, signed to Puértolas.To follow the Revilla option continue along the road towards Bielsa until Hospital de Tella. Follow the signs to Tella and then Revilla. Whenever possible park sensibly to sample the birdlife of the area. You could expect to see birds like Crag Martin, Alpine Swift, Bonelli's Warbler, Firecrest, Honey Buzzard, Woodchat Shrike, Ortolan Bunting and Rock Bunting. Drive on to Revilla, park, and walk to the viewing area. You rarely have to wait long before seeing a Lammergeier, but you may also observe Golden Eagle, Peregrine Falcon, Red-billed Chough, Black Redstart and Rock Thrush among others.