Dolmen of Aguas Tuertas Nature · Valle de Hecho, La Jacetania, Huesca Megalithic gallery grave located at 1,600 metres of altitude, at the entrance to the Aguas Tuertas valley, in the Pyrenees of Huesca, within the rich dolmen complex of the western Pyrenees. It is a simple dolmen with a single chamber, formed by three vertical slabs of sandstone and conglomerate and a large capstone measuring 2 by 2.70 metres; its inner chamber measures 2.20 by 0.75 metres. Studies date it to the 3rd millennium BC, at the end of the Eneolithic. No remains of the original tumulus survive. It was first studied by Martín Almagro in the 1940s, and it forms a group with the dolmens of Cardal and Puerto de Escalé. Photo: JuanFGastón (CC BY-SA 4.0) What to see and do in Valle de Hecho