At the top of New York City, in The Bronx, there's a mysterious building known for harboring Russian spies. So I investigated the building to learn more.
Declassified files about soviet spy craft: https://www.cia.gov/readingroom/document/cia-rdp90-00530r000300620021-3
The video about the compound being built: https://www.youtube.com/watch?v=uX_bcVuzvPQ