Dolmen of Guadalperal

The dolmen consists of 150 granite stones, called orthostats, placed in a vertical arrangement to form an ovoid chamber 5 metres (16 ft) in diameter. They are preceded by an access corridor about 21 metres (69 ft) long and 1.4 metres (4.6 ft) wide. The chamber, of the Anta type common in the west of the Iberian Peninsula, consists of 140 stones and was covered with a mound of earth and gravel; it is surrounded by another circular ring that contained the upper mound.

At the end of the corridor, at the entrance of the chamber, stands a menhir about two metres high with carving that might be a snake and several cups. According to the latest research, its elongated and wavy engraving is believed to be a representation of the Tagus River as it passes through the area. These figures may have served as protection for the site.

The monument was discovered in 1926 during a research and excavation campaign led by the German archaeologist Hugo Obermaier between 1925 and 1927. It could have been a solar temple and also have been used as a burial enclave. Roman remains found there, a coin, ceramic fragments and a grinding stone, indicate that at that time it was safely preserved from looting. Eleven axes, ceramics, flint knives and a copper punch were found in a nearby dump. A settlement dating to the time of construction was also found, which presumably housed the builders; Obermaier discovered houses, charcoal and ash stains, pottery, mills and stones to sharpen axes.