Significant findings include 34 bronze axes discovered in São Martinho de Bougado, now housed in the Sociedade Martins Sarmento in Guimarães.

Other notable prehistoric landmarks include rock carvings in the village of Maganha and the Castro of Alvarelhos, a fortified settlement classified as a National Monument in 1910.

During the Roman era, the Castro gained prominence due to its location along a key road linking Porto (Cale) and Braga (Bracara Augusta).

The area was part of the lands of the madequisenses, an ethnic group whose territory spanned from the Atlantic Ocean to the Serra da Agrela mountain range and from the Leça to the Ave rivers.

This document mentions Alvarelhos (alvarelios), São Cristóvão do Muro (sanctum christoforum), and Cedões (zadones), the latter located in Santiago de Bougado.

Following the old Roman road, Soult’s central column attempted to cross the Ave River at Barca da Trofa but encountered strong local resistance.

The Ave River and its tributaries suffered severe pollution, leading to the decline of aquatic ecosystems and the loss of traditional industries such as flax processing, hydraulic mills, and agriculture along the riverbanks.