Indigenous peoples of southwestern United States realized economic and social safety in thousand-year-old massive structures serving as combined social, administrative and ceremonial centers that still stand today. Known as The Cliff Palace, a stately series of attached dwellings housed the Anasazi, the ancestors of the peoples of the contemporary pueblos. The Palace is dated to between AD 1100 and 1200 and is located in Mesa Verde National Park, Colorado. About 300 feet long, The Palace at one time contained 150 rooms and 23 kivas, rooms dedicated to spiritual or community meetings, which were entered from the roof level by ladders. The Cliff Palace may have had a population of 120 people.