The Mesa Laboratory of the National Center for Atmospheric Research, located atop Table Mesa at the west end of Boulder, Colorado, 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 backdrop, the monolithic sandstone slabs called the Flatirons. The laboratory’s pristine mesa-top setting is maintained as a nature preserve.