The Lourdes SIGINT (Signals Intelligence) facility was the largest signals intelligence station operated by Soviet and later Russian foreign intelligence services outside of Russia. Located near Havana, Cuba, the facility covered 73 km² (28 sq mi) and was situated less than 150 km (93 mi) from Key West, Florida. Construction began in July 1962 during a period of heightened Cold War tensions between the United States and the Soviet Union.
The strategic location allowed for extensive electronic surveillance and intelligence gathering operations directed at the United States.