"CIA lost nine cores of plutonium in the Himalayas trying to construct a listening post in the 60s" - u/LordTin

"There's an encrypted art sculpture at the CIA Headquarters titled KRYPTOS. It's complete message has remained unsolved for over 30 years." - u/majorhigh

"The CIA sent its manual titled "Psychological Operations in Guerrilla War" to Nicaraguan rebels by balloon in March of 1984 during the Nicaraguan Revolution." - u/AutomaticWish

"The famous Saigon evacuation helicopter photo at the end of the Vietnam War was not from the US embassy, but from the roof of an apartment building that housed senior CIA personnel." - u/l11ll11ll1111\

"The Pond" was a small US government intelligence organization that operated from 1942 and 1955. It worked in 32 countries, and after WWII was set up as a corporation contracted to the State Department, later merged with the CIA. The US government formally acknowledged it in 2001." - u/saddetective87

"CIA satellites in the 1960s would jettison heat-shielded film canisters with parachutes back to earth, to be retrieved in mid-air by plane" - u/shoreyourtyler

"Operation Gold, where the CIA/MI6 tunneled under Berlin to intercept Soviet communications. Problem was the KGB had a double agent and knew about the plan from the beginning. When it was 'safe' to discover the tunnel the Soviets did so, causing much to the embarrassment of the West." - u/Status-Victory

"In 1944 the Office of Strategic Services (OSS; now the CIA) created top-secret manual titled "Simple Sabotage Field Manual" to assist training "citizen-saboteurs" in occupied countries like Norway and France." - u/batkc

"The CIA hired a magician named John Mulholland in the 1950s to write a "magic book" for spies. The manual explained how spies could use skills like sleight of hand to poison an enemy's drink, or to steal documents. Mulholland was also employed by the CIA to explore paranormal activities." - u/TheTriviaPage

"The night before Iraq invaded Kuwait there was a soar in pizza orders made by the CIA" - u/Multipace

"Part of the CIA's Memorial Wall is the Book of Honor which identifies agents who have died in the field. However, as of 2021, 37 of the 137 entries in the book have no names as the identities remain classified even decades later." - u/GentPc

"A KGB agent and a CIA agent became friends while trying to recruit each other; they knew the other was a spy and just didn’t talk about it"

"In May 25, 2003, two men boarded an empty Boeing 727 at an airport in Angola and flew off into the sunset. The FBI and CIA conducted a massive search, but neither the men nor the plane was ever seen or heard from again. it is one of the largest aircraft ever to disappear." - u/peta-chad88

"One of the prime movers behind the 1954 coup in Guatemala was the United Fruit Company. Although the operation was carried out by the CIA the UFC was deeply involved in advocating for the coup since its' operations were threatened by Guatemalan land reforms." - u/GentPc

"The CIA paid Vietnam War spies by ordering them items from the Sears catalog because the spies operated in areas that had a barter economy and didn't rely on cash" - u/CircusSeal

"One of the most high profile double agents during the Cold War was Kim Philby, who was at one point the liaison between the CIA and MI6. In 1955 foreign secretary Harold Macmillan told the Commons he was likely not a spy, which was disproved after Philby defected to the USSR in 1963." - u/UndyingCorn

"The A-12 and SR-71 were made mostly of titanium, which had to be sourced from the World's largest Titanium supplier, the Soviet Union. So, the planes we sent over to spy on them, were made of materials obtained from they through the CIA and a network of shell companies." - u/hoosyourdaddyo

"The CIA disguised seismometers as tiger poop to track Vietnamese troop movements during the Vietnam War." - u/I_Bang_Grannies

"Project Azorian. In 1974 the CIA built a gigantic claw and lowered it three miles to the bottom of the Pacific Ocean to snag the entire wreck of a sunken Soviet submarine. And they partially succeeded." - u/captureorbit

"The CIA recruited one of Fidel Castro's mistresses to kill him in 1960, giving her poison pills, but he found out. Handing her his gun, he dared her to shoot, but her nerves failed and they had sex instead." - u/Ganesha811