ElephantsWorld, a non-profit organization in Thailand, is a volunteer-run elephant rehabilitation center that cares for 15 elephants. Gaina (left) worked as a logging elephant for over 30 years and in the tourism industry as a trekking elephant for over 20 years. Kammoon (right) was born in 1949, and worked in the tourism industry entertaining in shows. She was not fed properly, and her owner withdrew her from performing after 50 years in the camp. She was used for begging on the street until she was rescued and sent to ElephantsWorld. Travelers can volunteer for days to weeks at a time to help with this remarkable sustainable travel project.