Large-scale hydraulic mining (ruina montium)
Minería hidráulica a gran escala (ruina montium)
- Date
- siglos I-II d.C. · confidence medium
- Place
- Las Médulas, Carucedo, León, Spain
- Credited to
- Roman engineers and miners; described by Pliny the Elder
- Field
- Tools
⚠️ Disputed: the sources disagree.
What it is
A Roman technique in which galleries are driven into a hillside, flooded with water brought along tens of kilometres of canals, and the hill is brought down so that the gold can be washed out of the debris. At Las Médulas (León) it produced the largest open-pit gold mine of the Roman Empire.
Pliny (Naturalis historia, XXXIII, 70-78) describes ruina montium in Hispania around AD 77, but it is not known whether it was a Hispanic invention or a technique already known elsewhere. Exploitation of Las Médulas is placed between the end of the Cantabrian Wars (c. 25 BC) and the 2nd century AD, with dating still under review.
What it led to
- Hispanic gold for the imperial treasury for two centuries
- large intake canals tens of kilometres long and washing tanks
- a transformed landscape and sedimentation in the Sil valley, now a World Heritage site
Built on
- Roman aqueducts and supply canals