An open space reserve, also referred to as open space preserve, open space reservation, green space, or just open space, is land that is protected from development in perpetuity. Open space reserves may be in urban, suburban, or rural areas. Open space reserves are established by the government for recreational, environmental, ecological, aesthetic, and other reasons, including the restriction of population growth in certain areas. Examples of open space preserves include the Upper Las Virgenes Canyon Open Space Preserve in the Simi Hills, and the Thousand Oaks Open Space System.