One of the most notable examples of megalithic architecture in the middle Tagus river basin, the megalithic complex of Guadalperal, in the Valdecañas reservoir about 180 kilometres west-southwest of Madrid (Spain), continues to be the focus of attention after it was completely exposed for the first time in 50 years by extreme dry conditions in the summer of 2019.
     Made up mainly of around 140 upright stones, the burial chamber would have been 5 meters in diameter with a triple line of stone slabs arranged concentrically around it, and a corridor almost 10 metres long guarded by a menhir and a stela with a serpentine figure carved into it. Raised in two different phases, the later construction dates to between the 4th and 3rd millennia BCE.
     Recorded in 1925, and excavated between 1925 and 1927 by the famous German prehistorian and geologist Hugo Obermaier, finds included mainly scrapers, points, flakes and scraps of flint, and quartzite carvings. Obermaier then directed the restoration and stabilization of the enclosure's uprights, and its protection with a perimeter brick wall to prevent the entry of livestock.
     The construction of the reservoir on the Tagus river in 1963 flooded the site, which has since only been visible in periods of prolonged drought, or due to the discharges for the regulation of the river flow. The situation in 2019 provoked a debate regarding the prehistoric complex, including a proposal to relocate the monument. A resolution by the Ministry of Culture in 2020 declared the enclave an 'asset of cultural interest', considering it essential to preserve its relationship with the landscape where it was built.
     Following another lowering of the water level in the summer of 2021, a team made up of restorers, archaeologists, a geologist and a biologist undertook consolidation and conservation work to counteract erosion caused by inundations and large numbers of visitors, renewing calls for its rescue.

Edited from RedHistoria (27 December 2021)