Cerro Rico de Potosí was accidentally discovered in 1545 by Diego de Huallpa, a Quechua silver miner for Spanish invaders, while he was searching the mountain for an Inca shrine or traditional burial offering. The red mountain, now known as Cerro Rico, sits nestled between the Porco and Sucre mines, which had previously been discovered, being at lower altitudes and therefore easier to mine. However, once Cerro Rico was found to carry predominantly silver ores, mining focus shifted to the harvesting of the more costly ore over ores like tin, zinc, and lead found in Porco and Sucre. Now one of the largest silver mines in Bolivia, and in the world, the Cerro Rico de Potosí mine to date has yielded an estimated 60,000 tons of silver, and deposits are thought to still contain estimated reserves of 1.76 billion ounces of silver and 540 million tons of ore grading 0.17% tin. The mine is located in the south of the country in Potosí Department.