The oldest structure on the CIA's campus is called "Scattergood"

The Scattergood-Thorne Conferencing Center, now an event site for the American spy agency, was once home to two pioneering women.

The CIA headquarters in McLean, Virginia, is one of the most secure and secretive compounds in the world. About 10 miles outside of Washington, D.C., it's where thousands of CIA officers work to protect against foreign threats. The oldest structure on campus is a four-story, Georgian revival-style house whose history and inhabitants may be surprising.