The Annex, also known as the Secret Annex, is a hidden space in Amsterdam where Anne Frank and her family, along with others, lived in hiding during World War II. They sought refuge from the Nazi regime, which was persecuting Jews. The Annex was located behind a movable bookcase in her father's office building, providing a secluded environment for the occupants. During their time in the Annex, Anne Frank kept a diary, documenting her thoughts and experiences. This diary later became famous as The Diary of a Young Girl, offering a poignant insight into the life of a young girl facing the horrors of war and oppression.