The Castro de Marcelín (a typical Galician fortified hilltop settlement), located in the municipality of Agolada, is an unexcavated archaeological site that combines the interest of an Iron Age fortified settlement with the presence of a group of petroglyphs in its surroundings. Access is on foot via a path, allowing visitors to approach the site within a natural setting that helps explain its strategic location in the landscape.
The settlement is situated on a natural elevation at about 660 metres above sea level, visually dominating the surrounding territory. The croa (central enclosure of a castro), or main enclosure, has an oval plan with approximate dimensions of 90 × 50 metres. The entire perimeter is surrounded by an earthen rampart, a defensive structure typical of Gallaecian hillforts, intended to reinforce the protection of the settlement.
On one side, the hillfort expands through an area interpreted as an antecastro (outer enclosure or extension of a castro located outside the main defensive area), with a crescent-shaped layout protected by a second earthen rampart. Part of these defensive structures, both in the antecastro and in the croa, have been partially altered by the construction of a track, but the site still remains a representative example of hillfort defensive architecture in inland Galicia.
Integrated into a natural environment of great scenic value, the Castro de Marcelín allows visitors to understand the organisation of ancient castro settlements and their relationship with the surrounding territory, making it a site of great historical and cultural interest.
