Keeper of the Lost Cities
Keeper of the Lost Cities is a fantasy series written by author Shannon Messenger. The first book shares the same title, and there are nine and a half books in this series as of October 4th, 2023: Keeper of the Lost Cities, Exile, Everblaze, Neverseen, Lodestar, Nightfall, Flashback, Legacy, Unlocked (considered "half" of a book; a guide to the world presented in the series that includes a novella), and Stellarlune.