This Bolivian stamp of 2006 commemorates the 400th anniversary of the founding of Oruro, an Andean town which has seen its "ups and downs" due to its focus on mining. Shown is the nearby Sajama National Park which includes the mountain Nevado Sajama. This is the highest peak in Bolivia at 6542 meters, or 21,463 feet. It is, however, only the 13th highest mountain of the Andes range.
From Wikipedia, "Nevado Sajama is an extinct volcano...it is a composite volcano consisting of a stratovolcano on top of several lava domes."