Which anime features a post-apocalyptic world where humanity lives in giant, walled cities to protect themselves from giant humanoid creatures?

Attack on Titan is set in a post-apocalyptic world where humanity is confined within enormous walled cities to shield themselves from the Titans, giant humanoid creatures that devour humans. The series follows Eren Yeager, his adoptive sister Mikasa Ackerman, and their friend Armin Arlert as they join the military to fight the Titans and uncover the truth behind their existence and the world they live in. The show is known for its intense action scenes, complex characters, and deep, evolving plot.