Albuquerque is the largest city in the state of New Mexico, United States. It is the county seat of Bernalillo County and is situated in the central part of the state, straddling the Rio Grande. Roughly half the people in New Mexico live in the Albuquerque area. Albuquerque is home to the University of New Mexico (UNM), Kirtland Air Force Base, Sandia National Laboratories, Lovelace Respiratory Research Institute, and Petroglyph National Monument. The Sandia Mountains run along the eastern side of Albuquerque, and the Rio Grande flows through the city, north to south.