The flash flood of the Arás ravine Historical milestone · Biescas, Alto Gállego, Huesca Image of Biescas, not of the place itself. A sudden flood of the ravine swept ten-ton boulders in 1996 onto the alluvial fan where a campsite had been authorized: 87 people died, 27 of them children, and another 183 were injured in barely a few minutes. 7 de agosto de 1996 Photo: Jean Michel Etchecolonea (CC BY-SA 3.0) What to see and do in Biescas