Longar

The hypogeum stands on the south face of the Alto de los Bojes at 750 m above sea level, reached by a signposted track from the road between Viana and Aras. The position suggests that its builders wished it to be visible and to dominate the territory: the view reaches the Ebro valley, and the monument lies close to the settlement.

Access to the chamber is by a corridor oriented to the south and lined with upright stones (orthostats), four on each side. The entrance to the chamber was marked by a vertical slab with a circular opening of about fifty centimetres in diameter, probably meant to seal the burial from the outside with a closure of stone or wood and so keep scavenging animals from the bodies. Only the lower part of this slab survives.

The chamber is dug into clay and has a floor of beaten earth. Its walls are lined with small, irregular sandstone masonry laid dry, without mortar, and the head of the chamber is circular. The roof consists of two large, roughly worked sandstone slabs from rocks outcropping nearby, which together weigh almost seven tonnes. The slab nearest the entrance split in half and buried the hypogeum, which favoured its preservation. By its type the monument has been compared with megalithic monuments of Extremadura, Andalucía and the Algarve, although those seem to be later.