In 1965 Mesa Lab architect I.M. Pei visited the site to inspect test slabs for the exterior of the building. The unique look of the lab's exterior is a result of "bush hammering" the poured-concrete surfaces. The mesa-top building is the headquarters of the National Center for Atmospheric Research (NCAR) and is recognized as one of Pei's major works. 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.