The Citânia de Briteiros is an archaeological site of Castro culture in the north-western Iberian Peninsula, significant for its size, urbanism, and architecture. Although primarily known for its remains of an Iron Age proto-urban hill fort (or oppidum), excavations at the site have revealed evidence of sequential settlements extending from the Bronze Age to the Middle Ages.
The visible ruins of the walled village or hill fort cover an area of about 24 hectares. The Briteiros site is called a citânia or cividade (from Latin civitas, city), due to its large size and city-like structure; other examples from the region and period include the Citânia de Sanfins and Cividade de Terroso.
The defensive system includes three lines of ramparts, with a partial fourth line to the north and a pair of moats. The preserved walls measure one to three meters thick and less than two meters high; a portion of wall restored by Martins Sarmento measures almost four meters high. The walls were built using irregular dry stone masonry methods, edged on both sides. The innermost rampart was partially absorbed into the urban development by being incorporated as a support wall for several family compounds. Gates were cut through each of the ramparts to provide passage; some of the gate openings still have hollows where vertically-moving palisades were placed. Ramps and stairs providing access to the top of the third rampart are evident
The known urban area of the settlement includes the acropolis, at the highest elevation, surrounded by the first rampart, and covering an area of about 7 hectares. Around 100 family dwelling compounds were found in this area, grouped into small blocks, with the blocks divided by several streets Briteiros is unusual among castros in having its streets arranged in a rough grid pattern. The ramparts and main roads form the most visible aspects of the urban organization for public use, but other community elements exist: conduits which carried water from a spring on the hill, fountains, at least two public bath structures, and a large meeting or council house.[1] One bath ruin, an accidental find during road work in the 1930s, is one of the best-preserved constructions of its kind in northern Portugal and Galicia[2], and includes a decorative monolith of almost 3 meters square, called the Pedra Formosa (the "handsome stone", thought once to have formed part of a burial chamber)
Each of the family compounds, delimited by masonry walls, provided living and working space for a large family. Most compounds included one to three circular stone houses, some of them large and with an atrium, where the nuclear family lived; other structures within the compound housed other family members, served as stables, or stored agricultural tools, food, and rain or spring water.
Daily tasks and crafts were performed in the stone-paved courtyard of the compound, which formed the center of family life in the citânia. Assuming around 6 people per family unit, a population of the acropolis of around 625 people has been estimated, but estimates may reach as many as 1500 for the entire settlement when excavations are made of the eastern and south-western extremities.