In terms of cultural heritage, the Santa Monica Mountains boast a rich history of continuous human occupation dating back more than 10,000 years and contain many nationally significant prehistoric and historic sites. In fact, more than 1,000 archaeological sites are located within the boundary of the Santa Monica Mountains National Recreation Area making it one of the highest densities of archaeological resources found in any mountain range in the world. There are twenty-six known Chumash pictograph sites with the national recreation area, all sacred to traditional Native American Indians, and include some that are among the most spectacular found anywhere. These pictographs - along with other sites - have been described by the National Park Service as unique and a significant world heritage.