Alcalar near Portimao
In the third millennium BC, the focal point of the territory stretching from north from the Alvor inlet to the foothills of the Monchique range was a settlement measuring over 10 hectares located at the end of a once navigable section of the Torre river.
This settlement stood on a hillock next to what is now Alcalar, some five kilometres from Mexilhoeira Grande, in the Portimão area and in the midst of the Algarve’s barrocal (limestone coastal strip).
Other inhabited sites grew up around this central settlement and around eighteen megalithic tombs were built in different groups on the surrounding low hills, forming a necropolis with a wide range of architectural styles.
Monuments 7 and 9 of the necropolis have been prepared for museum purposes and can be visited, although the latter is still being excavated. Monuments 1-4 are located on state-owned property and can also be visited.
More information at http://www.ippar.pt/english/monumentos/sitio_alcalar.html