Dolaucothi Gold Mine

The Dolaucothi Gold Mine is a Roman Gold Mine located near Pumsaint in the County of Carmarthenshire, Wales.

It was operated by the ‘Ruina Montium’ method, where water from reservoirs was used to flush out the mineral vein in a shaft.
Dolaucothi Gold Mine

In 74 CE Pliny the Elder was a Procurator in Hispania Tarraconensis. (Natural History 33.21).
His describes hydraulic mining in detail, which was probably based on practice observed at Las Medulas Gold Mine.

In 74 CE, Frontinus was sent to Britannia as Governor.
He subdued Wales and established Caerleon as the base for the Legio II Augusta.
The Legion built a series of forts, including a fort at Pumsaint next to the Goldmine. The Legion probably supervised the Mining Operations since Army engineers were attached to each Legion.

The technique described by Pliny the Elder was called ‘Ruina Montium’, meaning ‘wrecking the Mountain’.
Shafts were driven down into the mountain, water was then filled into the shafts, the pressure weakening the rock which disintegrated.
Aqueducts were constructed to bring the water needed for the mining operation.
Tanks and reservoirs were built near the vein to be exploited. They were fed by the Aqueducts. A huge volume of water, ‘Hushing’, was suddenly released, either sluicing away surface soil to reveal a vein, or removing the mineral vein from the surrounding rock in the shaft.
Whole hillsides could be flushed away by this method.
The ores were then washed in small streams, and through riffle tables. These have vertical bars which vibrate against the current, causing the Gold nuggets to fall out and separate from the ore as it hits them.
Burning, was an additional method used to loosen the rock, by lighting a fire beside the rock and letting the heat crack it.

Dolaucothi Gold Mines, Pumsaint