The Chalcolithic site of Valencina de la Concepción–Castilleja de Guzmán (Seville) is one of the most outstanding sites in Europe during the 3rd millennium BC. Among its most striking finds is the use of cinnabar (mercury sulphide), especially in the Tholos of Montelirio, where this intensely red mineral covers walls, anthropomorphic figures and funerary goods, creating a striking visual effect.
Due to its rarity and the difficulty of obtaining it, cinnabar was considered a luxury material, full of symbolism, and reserved for the funerary rituals of the elites.
Recent research has shown high concentrations of mercury among the people buried in Valencina. These remains show varying degrees of exposure to mercury, which is associated with handling the mineral, making paints, or rituals in which cinnabar was inhaled, ingested or absorbed through the skin.