The Yesa reservoir and the end of Tiermas and Escó Historical milestone · Sigüés, La Jacetania, Zaragoza Image of Sigüés, not of the place itself. The closing of the reservoir on the river Aragón flooded between 1959 and 1960 the best lands of the municipality and forced the abandonment of Tiermas, with its thermal baths that reappear when the water drops, and of Escó, left empty high on its slope. 1959 Photo: Allpe (CC BY 3.0) What to see and do in Sigüés