Megalithic Monuments of Alcalar
The Megalithic Monuments of Alcalar (Portuguese: Monumentos Megalíticos de Alcalar) are a group of burial tombs that comprise a Calcolithic necropolis, located in the civil parish of Mexilhoeira Grande, municipality of Portimão, Portugal. == History == During the 3rd millennium BC, a 10 hectare stretch of land, located at the end of a once navigable part of the Torre River became the centre of settlement.
Source: Wikipedia — Megalithic Monuments of Alcalar (CC BY-SA 4.0)