Inca agriculture was the culmination of thousands of years of farming and herding in the high-elevation Andes mountains of South America, the coastal deserts, and the rainforests of the Amazon basin. These three radically different environments were all part of the Inca Empire and required different technologies for agriculture. Inca agriculture was also characterized by the variety of crops grown, the lack of a market system and money, and the unique mechanisms by which the Incas organized their society. Andean civilization was "pristine"—one of six civilizations worldwide which were indigenous and not derivative from other civilizations. Most Andean crops and domestic animals were likewise pristine—not known to other civilizations. Potatoes and quinoa were among the many unique crops; Camelids and guinea pigs were the unique domesticated animals.