Washington, D.C. during the Cold War spared no expense in the pursuit of an information edge over communist adversaries, and the city is replete with examples of black budget spy houses and million-dollar listening tunnels.

One of the more unlikely (and low budget) points in the atlas of top secret spycraft is an unadorned attic space in Rock Creek Park where intelligence officers logged uncomfortable eight-hour shifts inside a former pigeon coop.

This modest spy station can be found atop a two-story blue granite shed beside the historic Peirce Mill, and just across the street from the Embassies of Hungary and Czechia (née Czechoslovakia). The aged structure was built as a carriage house in the 1820s and fell into National Park Service jurisdiction in 1936.

While the ground floor space was leased to an “alternative” art collective circa 1970, suit-wearing spies moved in up the creaky stairs behind a wooden partition and padlocked door. Here they peered out through grated windows, snapping pictures of the Warsaw Pact diplomats and monitoring bugging equipment directed at the diplomatic consulates.

The spy station was first brought to light in a 1992 Washington Post interview with Art Barn Executive Director Ann Rushforth, who explained that “We always knew which guys were the CIA guys because they always wore sunglasses indoors, had real sharp creases in their pants, short haircuts and shiny shoes.” The Post reported that all spy equipment had been removed the prior year and that the effort was actually FBI led, as the Bureau normally takes point on domestic counterintelligence.

Today the Art Barn is no more, and the ground floor of the carriage house is used for a small Park Service museum space. What was once a top-secret intelligence community perch is now blocked off by nothing more than a rope barrier.