Camp Peary in Virginia. It's the training ground for all clandestine services, famous for the CIA but DIA uses it as well as other branches/services.
1980 WaPo source: https://www.washingtonpost.com/archive/local/1980/02/19/down-on-the-farm-learning-how-to-spy-for-the-cia/fbe2f23c-ab8d-4fba-aab2-1c1da55f1c53/?noredirect=on&utm_term=.481df42fcef8