Elephants can be found in various captive facilities such as a zoo, sanctuary, circus, or camp, usually under veterinary supervision. They can be used for educational, entertainment, or work purposes. The earliest evidence of captive elephants dates to the Indus Valley Civilization about 4,500 years ago. Since then, captive elephants have been used around the world in war, ceremony, and for manual labor and entertainment. Captive elephants have been kept in animal collections for at least 3,500 years. The first elephant arrived in North America in 1796. London Zoo, the first scientific zoo, housed elephants beginning in 1831.