The Enchanted Castle is a fantasy novel by E. Nesbit. The story follows three children-Gerald, Jimmy, and Kathleen-who discover a hidden castle and meet a girl named Mabel, who claims to be a princess. They find a magic ring that grants invisibility and other strange powers, leading them into a series of mysterious and sometimes eerie adventures.

The novel blends realism and fantasy, a signature style of Nesbit's writing, and explores themes of imagination, friendship, and the unintended consequences of magic. It also has elements of humor and suspense, making it a captivating read for both children and adults.