Theresienstadt.
During the war, small bits of information about the extreme and horrific episodes perpetrated under the Third Reich reached an unbelieving world. The Nazis needed to answer the world's growing concern and yet they wanted to continue implementing their "solution" to the Jewish Question. The Nazis decided to use Theresienstadt to solve the growing outside pressure. Through deceit and subterfuge, the Nazis transformed Theresienstadt into a "model ghetto."
Also see, the Potemkin village and even the Potemkin President