Potosí is a department in southwestern Bolivia. It comprises 118,218 km² with 823,517 inhabitants. The capital is the city of Potosí.
It is mostly a barren, mountainous region with one large plateau to the west, where the largest salt flat in the world, Salar de Uyuni, is located.
Potosí was the richest province in the Spanish empire, providing a great percentage of the silver that was shipped to Europe.
Wikipedia https://en.wikipedia.org/wiki/Potosí_Department
Coordinates -19°35'21.498" N -65°45'12.531" E