[2] Notes by Martins Sarmento and from recent explorations show that the Monte de São Romão was a favoured location for rock art engravings of the Atlantic Bronze Age,[1] in the beginning of the first millennium BCE;[2][3] it is not known when or why this first group left.

Numerous early engraved rock surfaces were destroyed when many boulders were cut to build the ramparts and family compounds as the Castro settlement grew.

Evidence shows that there was a transitory reoccupation in the High Middle Ages, which included the building of a medieval chapel and graveyard on the acropolis.

[2] Sarmento's campaigns led to the discovery of much of the ruins of the acropolis (the highest portion of the settlement), and he reconstructed a pair of dwellings on the site from his research.

From the 1930s through the 1960s, new excavations were carried out by the Society, supervised by Mário Cardozo, which led to the discovery of large parts of the settlement on the eastern slope and additional portions of the acropolis.

In 2004 a project was initiated under the responsibility of Minho University with the collaboration of the Martins Sarmento Society to integrate the past studies and improve the conservation of the site.

[2] Between 1977 and 1978, archaeological interventions were handled by a team that included Armando Coelho Ferreira da Silva and Rui Centeno, from the Faculty of Letters of the University of Porto.

[2] Following excavations and surveys by archaeologist Francisco Sande Lemos, the Sociedade Martins Sarmento (UAM) proposed (in 2006) the creation of a proto-history biological estate, as a form of interpretative centre, alongside the site, to revitalize the location.

The moderate elevation of the site, the temperate and humid climate and the nearby river also provided rich natural resources for exploitation and settlement.

The ramparts and main roads are the most visible part of the site, although there are conduits that carried water from a spring on the hill, fountains, two public bath structures and a large meeting or council house.

[3] Including a decorative monolith of almost 3 square metres (32 sq ft), called the Pedra Formosa (the "handsome stone") thought to have once formed part of a burial chamber.