The Secret Annex was a hidden space located behind a movable bookcase in the building at 263 Prinsengracht in Amsterdam. It served as a refuge for Anne Frank, her family, and four other Jewish individuals during the Nazi occupation of the Netherlands in World War II. They lived there in secrecy for over two years, from July 1942 until August 1944. The annex was a cramped and confined area, consisting of a few small rooms. The occupants had to remain quiet during the day to avoid detection by the Nazis. Anne Frank documented their experiences in her diary, which later became famous worldwide as a poignant account of life in hiding.