Castro culture encompasses the northwestern regions of the Iberian Peninsula (roughly present-day northern Portugal, together with Galicia, Asturias, and northern and western León in Spain) from the end of the Bronze Age (c. 9th century BCE) until it is subsumed in local Roman culture.

The most notable characteristics of this culture are, first, its walled oppida and hill forts, known locally as castros, from Latin castrum "castle", and second, the absence of visible burial practices, while there were frequent depositions of prestige items and goods, swords and other metallic riches, in rocky outcrops, rivers and other aquatic contexts, since the Atlantic Bronze Age.

This cultural area extended east to the Cares river, and south beyond the Douro.The area of Ave Valley was the core region of this culture, with a large number of small Castro settlements, but also including larger and later oppida, the cividades (from Latin civitas, city), some known as citânias by archaeologists, due to their city-like structure: Cividade de Bagunte, Cividade de Terroso, Citânia de Briteiros, and Citânia de Sanfin