The Walls (壁 Kabe?) are three large structures located on the island nation of Japan. The Walls were erected roughly 100 years ago, around the time of the Great Titan War.
Description[]
The Walls are stated to be several stories tall, enough to keep the Titans outside away from the humans within. However, they were short enough for the Colossal Titan to be able to peer through.
History[]
The Walls were erected during or after the Great Titan War, in order to protect humanity from the Titans and the chaos ensuing in the rest of the outside world.
About 100 years later, the Walls would be breached by the Colossal Titan, who kicked a hole open in Wall Maria. This opening allowed Titans to enter inside and devour the people within.