The Santa Monica Mountains National Recreation Area (SMMNRA) is a United States National Recreation Area containing many individual parks and open space preserves, located primarily in the Santa Monica Mountains of Southern California. The SMMNRA is located within the greater Los Angeles region, with two thirds of the parklands in northwest Los Angeles County, and the remaining third, including a Simi Hills extension, in southeastern Ventura County. Overall administration is by the National Park Service, coordinating with state, county, municipal, and university agencies. The Santa Monica Mountains Recreation Area preserves one of the best examples of a Mediterranean climate ecosystem in the World. It also protects one of the highest densities of archaeological resources in any mountain range in the world.