The Aztec Ruins National Monument preserves ancestral Puebloan structures in the northwestern part of the U.S. state of New Mexico. This national monument is close to both the town of Aztec and the Animas River. It is about 12 miles (19 km) northeast of Farmington, New Mexico. The Salmon Ruins and Heritage Park, which also has Puebloan structures, is about 9.5 miles (15.3 km) south of the monument.