The fortified settlement of Citânia de Santa Luzia, known locally as Cidade Velha (Old Town), dates back to the Iron Age and Roman era and is considered one of the most significant castros in the North of Portugal. Its location was strategically chosen to control the entrances and exits at the mouth of Rio Lima, which was navigable for much of its course in Classical Antiquity.

Notably, Citânia de Santa Luzia has distinct architectural features, such as polygonal building stones used in some circular floor plans with a vestibule or atrium, and some even had ovens to bake bread. The settlement’s unique characteristics make it an important site for studying Protohistory and the Romanisation of the Alto Minho region. Its dominance over a large area of the riverside coastal area and control over the mouth of the Rio Lima further emphasize its historical significance.