I was able to finally stop in at I.M. Pei's stunning Brutalism for the National Center for Atmospheric Research's Mesa Laboratory. Shoehorned into the foothills above Boulder, Colorado, it's a gorgeous setting for a gorgeous set of buildings.
Pei designed the complex in the early sixties and chose bush-hammered concrete made from local pink aggregate to complement the mountains. The Anasazi cliff dwellings of Mesa Verde were his muse. Pei designed the nearby administrative offices in 1969.
The administrative building has a much lower profile and is sympathetic to the main complex: