Inspired by the legend of El Dorado, the realm of the gold-covered king.
After defeating the Inca army at the Battle of Cajamarca, their quest began in earnest.
At Potosi, in what is now Bolivia, the Spaniards struck it rich.
They discovered the Cerro Rico, literally the Rich Hill.
Towering nearly 16,000 feet above sea level, it was a money mountain.
In their 250 years of Spanish rule, more than 2 billion ounces of silver were extracted from mines like this one,14,000 feet up in the Andes.
What the Incas couldn't grasp was why the Europeans had such an insatiable lust for gold and silver.
They couldn't understand that to Pizarro and the Conquistadores, silver was much more than just shiny metal,
it could be made into money, a store of value, a unit of account, portable power.