In 1545, by Spanish account via an Andean prospector named Diego Gualpa, silver was found on a bare reddish peak at 4,000 metres in the high Andes — the Cerro Rico, the Rich Hill. The ore near the surface was so pure it could be smelted in wind-blown Andean furnaces. Within decades the mountain above the new city of Potosí was the most valuable piece of ground on the planet.
By 1600 Potosí held perhaps 160,000 people — larger than contemporary London or Seville — at an altitude where nothing grows and everything, from timber to mercury to luxury goods, arrived by llama train and mule. Spanish coins stamped from its silver circulated from Antwerp to Manila; the phrase vale un Potosí — “worth a Potosí” — entered Cervantes. A large share of all silver produced in the early modern world came out of this one mountain, and with it much of the money supply of Europe and, through trade, Ming China.
The mita
The price was paid underground. From 1573 the viceroy Francisco de Toledo adapted the Inca mit’a labour rotation into the colonial mita: Indigenous communities across a vast stretch of the Andes were obliged to send a seventh of their adult men to Potosí for a year’s turn. Workers descended by rope and notched-log ladders into tunnels lit by candle, hauled ore on their backs, and — after the rich surface ores gave out — processed it with mercury brought from Huancavelica, itself mined under the same system. Cave-ins, silicosis, cold, and mercury poisoning did the killing; communities held funerals for men before they left.
How many died is genuinely unknown. The popular figure of eight million belongs to legend rather than ledger, but the documented reality — a forced-labour system running two and a half centuries, feeding a mountain that consumed lungs at altitude — needs no inflation. Andean tradition kept its own account: the Cerro as a devouring deity, and the miners’ devil-figure El Tío, whose statues still receive cigarettes and coca in the tunnels today.
The hollow mountain
The silver thinned through the 1700s; the mita was abolished with independence in 1825; and Potosí declined into the altitude-bitten provincial city it remains — in one of the poorer countries of the continent, a standing exhibit for the argument that extracted wealth enriches everywhere but its source.
The Cerro Rico is still being mined, now mostly for tin and zinc, by cooperatives working a mountain so riddled with centuries of tunnels that its summit has begun to sink — UNESCO lists the site as endangered, and engineers have filled the crown with cement to slow the collapse of the hill that paid for an empire.