Ventamillo Gorge Nature · Chía, La Ribagorza, Huesca The Ventamillo gorge is the defile that the Ésera river opens between the Chía mountain range and the Turbón range, in the Ribagorza of Huesca, with vertical walls of more than 300 metres that narrow to barely 2,200 metres in its central stretch and extend along some ten kilometres of limestone rock. It was formed by the erosion of meltwater following the retreat, some 40,000 years ago, of the Ésera glacier, which reached as much as 36 kilometres in length. The road that runs through it, today the N-260, was opened in 1916 to give access to the Benasque valley. On its walls grows the endemic plant Petrocopsis pseudoviscosa, and wallcreepers, bearded vultures and golden eagles fly over the canyon. Photo: Cherubino (CC BY-SA 3.0 es) What to see and do in Chía