Hard rock gold mining in the Ancares basin happened in two specific places: As Labradas (Pereda de Ancares), overlooking the river –which is also known as Cuiña in the upper reaches–, and Las Cavanías and A Regueira das Meixoncías (Candín), overlooking the Seco River. Both are close to each other, and they share both geological and technical characteristics. The Quartz reefs that harbor the gold are associated with quartzite, slate and shale rocks created during the Cambrian-Ordovician period Cabos series. Later erosion have altered the material, allowing later mining to focus on the more altered surface rock in situ, or in scree found near the reefs.
The mine of As Labradas has been altered by modern iron mining in the higher part, as well as by a track that crosses the mining front. Otherwise the Roman mine structures are perfectly visible. Part of the hydraulic network is also visible: two deposits and some sections of the channels that brought the water from the headwaters of the Cuiña/Ancares. The tailings of gangue are deposited down the slope all the way to the River. The mine pit is some 800 m long and with a maximum width of 80-100 m. There are some indications of possible ancient galleries, covered or concealed by the recent mining.
The technique used was the arrugia, galleries pierced the placer deposit and later, in combination with hydraulic force powered or mechanical methods, it brought down the placer deposit. The water then washed away the gangue and freed the richer ore for later crushing and panning.
In one of the deposits of this hydraulic system a microtopography and archaeological sondage was carried out to ascertain its characteristics. This deposit is A Aira da Reibón, immediately north of the mine. This piscina has been altered by the track that crosses it, as well as by a recent water pipe and the afforestation of hardwood trees. Nonetheless, the southern end is in good condition, and the embankment that encloses the deposit, as well as the later sedimentation that filled it.
The excavation has revealed the large embankment built to lock in the water, as well as how the terrain was prepared for this reservoir. Also, some levels have been identified with the time in which this deposit was being used, as well as the history of how it later was filled until its present flat form.