The "castros", as the fortified settlements that crown many of the hills in the northwest of the Iberian Peninsula are usually called, are one of the most monumental expressions of the intense occupation of the territory during the so-called Iron Age, which is thought to have peaked between the 2nd century BC and the 1st century AD.
There are nine fortified settlements in the TVAP area, located on the headlands and promontories bordering the Terva Valley. They vary in size and all have solid walls, the smallest with just one line and the largest with more complex systems of two or three lines of walls, such as the Hillfort of Sapelos.
THE TVAP INTERPRETATION CENTRE PROVIDES ADDITIONAL INFORMATION ON HOW TO FOLLOW THIS ROUTE.
The extraordinary occupation density of the Terva Valley seems to be related to the intentional exploitation of existing mineral and metalliferous resources (gold and tin deposits).
Hillfort of Cabeço
Hillfort of Nogueira
Hillfort of Murada da Gorda
Hillfort of Muro de Cunhas
Hillfort of Sapelos
More about the Terva Valley Archaeological Park (TVAP) here.
English (UK) 
Português