The story begins in 1954, when researchers from the science faculty of Kyoto University started feeding the wild Japanese macaques of Iwatayama. Food drew the monkeys to a feeding place, and once they gathered there reliably, the site could be prepared for visitors. In March 1957 it opened to the public as a park, covering roughly 6,000 square meters. The land itself came from a local businessman named Sonosuke Iwata, whose family name is also the name of the mountain. He donated the ground where the park and its visitor facilities now stand, and he financially supported the park's operations until 1974. Then, because of financial difficulties, the park was sold to Kyoto City. The early years were not entirely smooth. At the start about 50 macaques were counted, and the troop grew so much that at one point it caused crop damage in the surrounding area. Today about 120 monkeys live here, and the way people behave around them is a large part of why that arrangement works.