In 1544, the Spanish Conquistadors discovered the silver mines in a city now called Potosí, which is on the base of Cerro Rico (Rich Mountain) in Bolivia. Almost immediately, they began enslaving the natives as workers in the mines. However, the health of the natives working in the mines became very poor, which is why the Spanish began to look towards a new group for labor. By the beginning of the seventeenth century, the Spanish mine owners and barons began bringing in African slaves in high numbers to help work the mines with the natives who were still able.