Aztec Ruins National Monument, 318 acres (129 hectares), NW N.Mex., near Farmington; est. 1923. Ruins of a 12th-century Pueblo town contain interesting kivas, one of which has been completely restored. Pueblo culture reached a high level of achievement in this area. The ruins were named by early settlers who mistakenly believed that they were built by the Aztecs. See National Parks and Monuments, table.