Potosi is a city and the capital of the department of Potosi in Bolivia. It is claimed to be the highest city in the world at a nominal 4,090 m (13,420 feet). It lies beneath the Cerro de Potosi sometimes referred to as the Cerro Rico ("rich mountain") a mountain popularly conceived of as being "made of" silver ore, which has always dominated the city. The Cerro Rico is the reason for Potosi's historical importance, since it was the major supply of silver for the Spanish Empire. Cerro de Potos's peak is 4,824 meters (15,827 feet) above sea level.
There is no satisfactory etymological study of the word Potosi. According to legend, circa 1462, Huayna Capac, the eleventh monarch of Peru, "set out for Ccolque Porco and Andaccaua, the location of his mines from which were taken innumerable arrobas of silver." (An arroba is a Spanish unit of weight equivalent to approximately 25 pounds.) "Before leaving there, he saw , and admiring its beauty and grandeur, he said (speaking to those of his Court): 'This doubtless must have much silver in its heart'; whereby he subsequently ordered his vassals to go to Ccolque Porco ... and work the mines and remove from them all the rich metal. They did so, and having brought their tools of flint and reinforced wood, they climbed the hill; and after having probed for its veins, they were about to open those veins when they heard a frightening thunderous noise which shook the whole hill, and after this, they heard a voice which said: 'Do not take the silver from this hill, because it is destined for other masters.' Amazed at hearing this reasoning, the Incan vassals desisted in their purpose and returned to Porco and told the king what had happened; relating the occurrence in their own language, on coming to the word noise, they said 'Potocsi' which means there was a great thunderous noise, and from that later was derived (corrupting a letter) the name of potosi.