On the north side of Telegraph Hill is 225 Chestnut St., a swanky modernist building. From 1955 to 1965, this building was the site of Operation Midnight Climax" - a top-secret mind-control program in which CIA agents used hookers to lure unsuspecting johns from North Beach bars to what they called "the pad," then dosed the men with LSD and observed the X-rated goings-on through a two-way mirror. As John Marks notes in his 1977 book, "The Search for the 'Manchurian Candidate': The CIA and Mind Control," the CIA's ... predecessor, the Office of Strategic Services, set up a "truth drug" program whose purpose was to discover a substance that would make subjects reveal their secrets. When the CIA was created in 1947, it ... authorized covert mind and behavior control programs. Drugs were given to people deemed expendable, including North Korean POWs, mental patients, prisoners, addicts and prostitutes. Before the programs were shot down, hundreds of scientists would work on them. [In] 1953, CIA director Allen Dulles approved a program for "covert use of biological and chemical materials" with an initial budget of $300,000. Its name: MKULTRA. CIA operatives began dosing people with acid in restaurants, bars and beaches. They also used other, more exotic drugs. And the agency began using the prostitutes to lure men of all sorts, not just marginal figures, back to the safe house. Because the agency destroyed most of MKULTRA's files, no one will ever know how many lives and minds [it] damaged or destroyed.