The Anta de Adrenunes, located on top of a hill at 426 metres above sea level, in the municipality of

Sintra Sintra (, ) is a town and municipality in the Greater Lisbon region of Portugal, located on the Portuguese Riviera. The population of the municipality in 2011 was 377,835, in an area of . Sintra is one of the most urbanized and densely populated ...

, within

Sintra-Cascais Natural Park The Sintra-Cascais Natural Park is a park on the Portuguese Riviera, one of the 13 Natural Parks of Portugal. While only established in 1994 as a Natural Park by the Portuguese Government, it has been protected since 1981. Its area is approximate ...

Lisbon District Lisbon District ( pt, Distrito de Lisboa, ) is a district located along the western coast of Portugal. The district capital is the city of Lisbon, which is also the national capital. From its creation until 1926, it included the area of the cur ...

Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...

, is believed to be a Stone Age

burial chamber A chamber tomb is a tomb for burial used in many different cultures. In the case of individual burials, the chamber is thought to signify a higher status for the interred than a simple grave. Built from rock or sometimes wood, the chambers could a ...

megalithic A megalith is a large stone that has been used to construct a prehistoric structure or monument, either alone or together with other stones. There are over 35,000 in Europe alone, located widely from Sweden to the Mediterranean sea. The ...

monument. It is a structure consisting of a cluster of granite stones, between which there is a gallery about 5 metres high that is surmounted by

monolith A monolith is a geological feature consisting of a single massive rock (geology), stone or rock, such as some mountains. For instance, Savandurga, Savandurga mountain is a monolith mountain in India. Erosion usually exposes the geological for ...

s that rest horizontally on vertical stones. The passage is thought to have served as a collective

necropolis A necropolis (plural necropolises, necropoles, necropoleis, necropoli) is a large, designed cemetery with elaborate tomb monuments. The name stems from the Ancient Greek ''nekropolis'', literally meaning "city of the dead". The term usually im ...

or dolmen during the megalithic period although no artifacts or burial chambers have been found to prove this. The site contains a geodesic landmark that has been inserted into one of the upper stones. Initial excavations by Joaquim Possidónio Narciso da Silva (1806-1896) found no evidence of funerary use. However, Da Silva presented the results of his research at one of the sessions of the International Congress of Anthropology and Prehistoric Archeology in 1871, referring to the site as a megalithic funerary monument. Later writers have argued that the site combines natural granite rocks, which are also found elsewhere in the area, with some architectural elements. They point to the layout of the rocks and their orientation to the sunset to argue that this suggests a megalithic structure that was probably of natural origin and was later worked on by humans. More recent excavations of the stones have provided some evidence of the intervention of humans, as granite wedges in the foundations of some of the stones have been identified. The approximately rectangular shape of some of the rocks also provides possible evidence of human intervention, although other writers have argued that the site is no more than a natural collection of rocks. AntadeAdranunes1

Visiting the site requires a walk of about one kilometre from a tarred road. It receives relatively few visitors, although it is popular at the time of

solstice A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countr ...

s and

equinox A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and se ...

es.

References

{{European Standing Stones National monuments in Lisbon District Megalithic monuments in Portugal Prehistoric sites in Portugal Stone Age Europe Dolmens in Portugal