Viewed from the air, the Mesa Laboratory headquarters of the National Center for Atmospheric Research and its extensive horseshoe-shaped parking area stand firmly astride their mesa-top site of more than 400 acres (160 hectares) at the southwestern edge of Boulder, Colorado. The Mesa Laboratory is recognized as one of the major works of architect I.M. Pei. Completed in 1966, the laboratory strikes many viewers as futuristic, but its design was strongly influenced by the ancient Indian cliff dwellings of Mesa Verde National Park in Colorado. With walls of reinforced concrete colored by locally quarried stone, the building harmonizes rather than competes with its dramatic setting. The laboratory's pristine mesa-top setting is maintained as a nature preserve.