The department of Potosí is in southwestern Bolivia. It comprises 118,218 km² with 709,013 inhabitants (2001 census). 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. It is also the location of the San Cristobal mines presently being developed by American company Apex Silver Mines Limited of Colorado.