Apenheul Primate Park opened in 1971 as a small but revolutionary park housing wool-monkeys and other species. It is located in the nature park of Berg en Bos (Mountain and Wood) and proved popular with visitors and primatologists alike, leading to subsequent expansions. In 1976, gorillas were introduced to Apenheul Primate Park, with the first gorilla baby being born three years later. This was only the second healthy baby that had born in captivity in the Netherlands and the third in the entire world. The baby was raised by its own mother, which remains a rare event.