The Anta de Agualva, also known as the Anta do Carrascal, is 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 ...

dolmen A dolmen () or portal tomb is a type of single-chamber megalithic tomb, usually consisting of two or more upright megaliths supporting a large flat horizontal capstone or "table". Most date from the early Neolithic (40003000 BCE) and were somet ...

situated in an urban area of

Agualva-Cacém Agualva-Cacém () is a Portuguese city located in the municipality of Sintra. It comprises the civil parishes of Agualva, Cacém, Mira-Sintra, and São Marcos, equivalent to 81,845 inhabitants of the municipalities population. History The name ...

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 ...

, in the

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 ...

. First identified by

Carlos Ribeiro Carlos Ribeiro (21 December 1813, in Lisbon – 13 November 1882, in Lisbon) was a pioneering geologist and archaeologist who inaugurated the concept of fieldwork in Portugal, and was responsible for the discovery and excavation of many Neolithic ...

in 1875, the dolmen has recently been restored and can be easily visited. The dolmen is believed to have been made up of a polygonal chamber measuring 3.7 × 3.8 meters and formed by seven vertical stones (

orthostats This article describes several characteristic architectural elements typical of European megalithic (Stone Age) structures. Forecourt In archaeology, a forecourt is the name given to the area in front of certain types of chamber tomb. Forecourts ...

), together with an access corridor. Three large blocks have also been identified that may be fragments of the stone that covered the tomb. A few archaeological fragments were found at the site and they are now deposited in Lisbon's Geological Museum but many more were believed to have been taken prior to Ribeiro's excavations. The artifacts collected, as well as more recent

radiocarbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was dev ...

, suggest that the chamber was used in the late-

Neolithic The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several parts ...

period between the middle and end of the 4th millennium BC. Later, in the second half of the 3rd millennium or in the second millennium, additional funerary deposits may have been made in the access corridor. The Anta de Agualva was first identified in 1875 by military engineer and geologist Carlos Ribeiro who excavated this site as well as several other dolmens in the area to the northeast of

Lisbon Lisbon (; pt, Lisboa ) is the capital and largest city of Portugal, with an estimated population of 544,851 within its administrative limits in an area of 100.05 km2. Grande Lisboa, Lisbon's urban area extends beyond the city's administr ...

, such as the

Anta da Estria The Anta da Estria is a megalithic dolmen situated between Belas and Queluz in the Lisbon District of Portugal. Based on datings of human remains, it is believed to date back to the late-Neolithic and early-Chalcolithic eras (4000-2500 BC). The ...

, Anta da Pedra dos Mouros, Anta das Pedras Grandes, and

Anta do Monte Abraão The Anta do Monte Abraão was a megalithic dolmen located in the parish of Monte Abraão, in Queluz, Sintra Municipality, Lisbon District, Portugal. The dolmen was first identified in 1876, by Carlos Ribeiro, who carried out excavations until 1 ...

. The dolmen was registered as a national monument in 1910. In 1944,

Georg and Vera Leisner Georg and Vera Leisner were married German prehistorians and archaeologists who, after becoming a Lt Colonel and a nurse, spent many years studying fourth and third millennia BCE megalithic sites in Iberia. The work of the Leisners is widely ackno ...

drew up a new plan of the monument similar to that of Ribeiro but, in their case, assuming the existence of a significant

tumulus A tumulus (plural tumuli) is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds or ''kurgans'', and may be found throughout much of the world. A cairn, which is a mound of stones buil ...

. Further excavations were carried out in 1958 by Veiga Ferreira. The conservation of the monument has always presented problems related to the lack of clearance of the bush and to urban pressure. In 1994 the

Archaeological Museum of São Miguel de Odrinhas The Archaeological Museum of São Miguel de Odrinhas in Sintra municipality, Lisbon District, Portugal owes its existence to the collection by the Hermitage of São Miguel of Epigraphy, epigraphic stones found amongst the Roman ruins in the neigh ...

carried out a set of actions to safeguard the monument, including clearance of the area. In 2004, a park was inaugurated, denominated "Jardim da Anta" (Garden of the Anta), with the dolmen integrated in the landscaping. In 2017, at the initiative of Sintra City Council, work was carried out on the preservation and restoration of the monument and it was formally opened in April of that year.

References

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