Green Bank, West Virginia
NRAO is the constructor/owner of the worlds largest fully mobile radio telescope, the GBT, which resides in Green Bank, West Virginia. Green Bank is also the home of NRAO's prinicipal observatory as it is the center of a United States national radio quiet zone, which NRAO is also responsible for maintaining.
Offices are located on the University of Arizona campus. Formerly operated the 12 meter telescope on Kitt Peak. That telescope has been shut down and funding rerouted to the Atacoma Large Millimeter Array (ALMA) instead.