No one really knows. According to the limited amount of available history, they appeared over a hundred years ago to protect what was left of humanity from the titans. There's even a group of cultist creeps that believe the walls are a divine gift from some god.
[and an apparent conspiracy about the true origins of the walls having been covered up, but that's too much information that they're still in the process of sorting out themselves. And potentially dangerous.]
no subject
[and an apparent conspiracy about the true origins of the walls having been covered up, but that's too much information that they're still in the process of sorting out themselves. And potentially dangerous.]