"City of Walls and Secrets" is the fourteenth episode of the second season of the American animated television series Avatar: The Last Airbender, and the 34th episode overall. The show follows Aang, the last airbender and the “Avatar”, on his journey to bring balance to a war-torn world by mastering all four elements: air, water, earth, and fire. On his quest, he is joined by companions Katara, Sokka, and Toph Beifong, and hunted down by Fire Nation prince Zuko and princess Azula. The episode was written by Tim Hedrick and directed by Lauren MacMullan.

Book Two: Earth is the second season of Avatar: The Last Airbender, an American animated television series created and produced by Michael Dante DiMartino and Bryan Konietzko for Nickelodeon. The series starred Zach Tyler Eisen, Mae Whitman, Jack DeSena, Jessie Flower, Dante Basco, Dee Bradley Baker, Mako Iwamatsu and Grey DeLisle as the main character voices.