Archaeologists working in north-western Spain are investigating an extraordinary rock engraving described as “unique in Europe”, as part of a wider project exploring what researchers believe was a prehistoric sacred landscape.
The discovery is being studied during the fourth archaeological campaign at Santa María Madalena de Adai, in Lugo, Galicia, where researchers are examining a landscape containing petroglyphs, burial mounds and rock shelters.
Led by University of Santiago de Compostela (USC) professor and CISPAC researcher Pilar Prieto, the latest campaign began on 31 August and is due to conclude on 18 September 2026.
At the centre of this year’s work is an unusual petroglyph depicting what researchers interpret as the floor plan of a hut covering approximately 40 square metres.
According to Prieto, the engraving is unique in Europe and could help researchers build a more complete understanding of what she describes as a “sacred landscape” surrounding Adai.
Mysterious engraving carved into the rock
The team is currently investigating two rock shelters at Penas do Caldeiro.
One, known as Pena Travesa, features a petroglyph containing complex arrangements of cup-like depressions carved into the upper surface of the rock.
The second site has attracted particular attention because of the large engraving interpreted as the base or floor plan of a prehistoric hut.
At approximately 40 square metres, its scale and design distinguish it from other known examples and could offer archaeologists an unusual insight into the symbolic significance of domestic architecture in prehistoric communities.
Rather than examining the engraving in isolation, the researchers are studying it as part of the wider archaeological landscape.
A landscape filled with prehistoric monuments
The latest campaign builds on excavations conducted at nearby Corro dos Mouros between 2023 and 2025.
As work has expanded across the area, archaeologists have continued to identify previously undocumented sites. The current research has resulted in the cataloguing of six new cairns and two additional petroglyphs, adding to the growing concentration of archaeological remains known around Adai.
Together, the rock art, shelters and burial monuments could help researchers understand how prehistoric communities moved through the landscape and how particular natural features acquired ritual or symbolic significance.
The project therefore aims to reconstruct not simply individual archaeological sites, but the relationship between monuments, settlements and the surrounding terrain.
Searching beneath the surface
Researchers are also preparing to investigate what may remain hidden underground.
Geophysical surveys are planned for the end of September. These non-invasive techniques will allow archaeologists to search for potential buried structures without immediately excavating them.
Any anomalies identified during the survey could help determine where future excavations should be concentrated and reveal whether additional archaeological remains connect the currently known sites.
The results may ultimately provide a clearer picture of how the landscape developed and was used over time.
Header Image Credit : Adrián Folgueira
Sources : USC
