"Ronja" is a children's book written by Swedish author Astrid Lindgren. It tells the story of a young girl named Ronja who lives in a forest and is the daughter of a robber chief. The narrative explores themes of friendship, bravery, and the struggle between good and evil as Ronja befriends a boy from a rival clan. The book is set in a magical forest filled with mythical creatures and natural wonders. It emphasizes the importance of nature and the bond between Ronja and her surroundings. "Ronja" has been adapted into various films and stage productions, further popularizing the story.