The southwestern region of the
Iberian Peninsula is a focus of
Megalithism, predating by 1000 years the megalithic region of western
France: The erection of
dolmens,
menhirs and castros developed over a long period of southern and central Portugal. At about the beginning of the 3rd millennium BCE, contemporaneous with metallurgy associated with the copper and precious metals, new types of tomb-building appeared in the western Mediterranean regions. There has been some debate as to whether these developments originated in the Eastern Mediterranean or whether they are independent of these cultures, although there is little evidence to support the hypothesis, other than the use of the term
tholoi (which can be seen as a more contemporaneous development).
VNSP I It has been determined that early inhabitants in this region began building fortifications around 2700 BCE, with the Dolmen of Herdade de Zambujal being the more central, with a very complex plan and up to six reconstructions in its lifetime. These cultures left behind many traces of their culture: stylized cups, crescents of clay, sticks of slate and the so-called plate-idols, that some archaeo-astronomers consider to be precise calendars. Nevertheless, the exchange with other groups, particularly
Los Millares, is also present in the archaeological record. The inhabitants of the fort had its economy based on agriculture and grazing, which was suitable to the surrounding lowlands.
VNSP II But, trade proved to have greater interest: the first settlers brought with them red-tinged pottery, more delicate then later ceramics, with excellent decoration, suggesting their contact with peoples of a superior civilization (something that they could not produce with similar quality). With the arrival of the
Beaker peoples around 2200 BCE, the local culture entered a new period of development that mixed the Beaker people burial rites, while maintaining other traditions. It is likely that the Beaker people's presence within this region also resulted in secondary phase of development of this culture. The inter-cultural exchanges between groups were more frequent, and their influence spread to distances of 1000 kilometres or greater, as was the case with the
Treilles, in the French Languedoc. Local artifacts associated with these cultures, such as the
Palmela arrowheads or bell-shaped beakers, were commonly found dispersed in the western half of the Iberian peninsula, suggesting an origin in the region. After 1900 BCE there is a decentralization in the Iberian peninsula, resulting in a dispersion of many of these artifacts to as far as
Bohemia. With the arrival of
Bronze Age technologies in southern Iberia after 1800 BCE (particularly in
El Argar), the influence of the castro culture of Vila Nova de São Pedro begins to slowly decline. Finally, around 1300, it merges with the wider culture associated with internally burnished pottery, including most of Portugal and the wider
Atlantic Bronze Age cultures. ==Excavations==