The Walls (壁 Kabe) are three large structures located on the island of Paradis. They were built by the 145th King of Eldia, Karl Fritz, more than a century ago using countless Colossus Titans, and surround the territory where he fled with many of his people, the Eldians. The Eldians inside are taught that they are the last remnants of humanity who built the Walls to protect themselves from the Titans.

Description:
The Walls reach about 50 meters in height from bottom to top and are incredibly strong in substance. The Walls are too long to be guarded in their entirety. The tops of the Walls are lined with cannons mounted on rails which can fire on approaching Titans; however, they are not particularly effective due to the Titan's regeneration abilities. To account for this, each Wall has four towns on their periphery known as "districts." As Titans are drawn towards large concentrations of people, humanity can focus its defenses on these districts and repel the Titans more effectively. The districts are considered the worst places to live as they are at greater risk of a Titan invasion. Few people know about the Titans within the Walls, or that they were created from Titans. Some members of the Church of the Walls considers the Walls to be holy, knew of the Titans within them, but did not reveal any more information.

Wall Maria:
Wall Maria is the outermost Wall of the human kingdom. Like the other Walls, Wall Maria is approximately 50 meters in height.

Wall Rose:
Wall Rose is the second outermost Wall following Wall Maria.

Wall Sheena:
Wall Sheena is the innermost Wall protecting the kingdom where the king and other civilians reside. The cities of Wall Sheena are protected by the Military Police serving under the king. The underground is poorer and more prone to criminal activity.