Directions Gold Mining Sites at Montefurado
Montefurado, in the municipality of Quiroga, contains one of the most important gold deposits exploited by the Roman Empire, and the area was declared as a Place of Geological Interest (LIG) in 1983. The Romans excavated the Iberian Peninsula’s largest tunnel in this location, to facilitate their extraction of this precious metal.
The Romans mined gold in Montefurado in two different ways.
The first can be seen in the village of Montefurado itself, as well as in the vineyards located to the south of the village, where Roman miners took advantage of gold deposits in the surrounding rock. These are Miocene-epoch conglomerates, primarily quartzite. There are outcroppings of this type of stone along both sides of the Sil River, and their matrix consists of sand, lime, and clay, which gives them a reddish colour. The thickness of the deposits in the Montefurado area never exceeds 20-30 metres.
The second type of deposit the Romans exploited were Quaternary-period alluvial deposits, using the procedure known as placer mining. In this case, sands, gravels, and silts from the Sil riverbed and the adjacent floodplains and alluvial terraces were exploited, by redirecting the course of the river through the Montefurado Tunnel. These deposits were generally shallow, with irregular thickness, but when heavy rains fell during their formation, they were enriched with fragments of gold coming from upstream source areas. To extract this gold, the Romans diverted the flow of the Sil River by creating the Montefurado Tunnel. Forcing the river to flow through the tunnel dried out a large meander, which could then be more easily mined.
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A good place to observe these ancient gold deposits is the Anguieiros Viewpoint, which provides a good perspective over the Montefurado Tunnel and the lands mined by the Romans.
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