In Attack on Titan, the "Three Walls" are colossal structures that serve as humanity’s primary defense against the Titans, terrifying, giant humanoid creatures that have pushed humanity to the brink of extinction. These walls—Maria, Rose, and Sina—are not just physical barriers; they represent the last remnants of human civilization in a world where Titans roam freely outside their safe zones. The walls are fundamental to the series' setting, shaping the lives of the characters and the trajectory of the plot, as the struggle for survival and the mystery of the Titans and the walls themselves are central to the narrative.
Using the power of the Founding Titan, Karl Fritz erected three walls. These walls, formed by tens of millions of Colossal Titans, have served as a shield and spear, safeguarding peace.
— Willy Tybur recounts the formation of the Walls
The Walls were three large structures located on Paradis Island that guarded the remnants of Eldia. They were built by the 145th King of Eldia, Karl Fritz, more than a century ago using countless colossal-sized skinless Titans which were contained inside the Walls' hollow core. They stalled the other nations from attacking Paradis, under the false threat that the King would unleash the Titans inside upon the world if they did so. The Walls crumbled about a century later when Eren Jaeger used the power of the Founding Titan to free the Titans within them
The Walls reached about 50 meters in height from base to summit and were incredibly strong in substance. However, the Female Titan was able to damage one of them when she attempted to climb over it, and the Beast Titan was able to break off pieces of Wall Rose and throw them.
The distance from Wall Maria to Wall Rose was said to be about 100 km, the distance from Wall Rose to Wall Sina about 130 km, and the radius of Wall Sina about 250 km. Assuming the Walls to be perfect circles, this would have made the total perimeter of Wall Maria to be around 3,016 km with the total area inside the Walls being 723,822 km².
One hundred and seven years ago, it is said that humans were brought to the brink of extinction at the hands of the Titans. In response to this, the survivors made huge Walls to protect their last stronghold. In reality, however, The 145th King Karl Fritz decided to end the Great Titan War and the fighting within the Eldian Empire by withdrawing to Paradis Island, taking as many of his people with him as he could. He then used the power of the Founding Titan to create Colossal Titans to form and enclose within three concentric Walls; which would be named after Ymir Fritz's three daughters; Sina, Rose, and Maria. After Marley started sending Pure Titans to the island, the Eldians inside were taught that they are the last of humanity who built the Walls to escape the Titans.
In an attempt to isolate his people and create a peaceful utopia for them as long as possible, Karl Fritz told the world that any attempt to attack the Walls would result in him unleashing millions of Colossal Titans inside the Walls to flatten the entire earth. Then, to ensure the Founding Titan would never be used for war, he made a vow to renounce it, and his will was passed down to all his descendants.
Fritz realized that this would leave his people defenseless, but decided that if Marley wished to exterminate all Eldians, they should accept it because of how grave the Eldian Empire's crimes against the world had been. But until that day, he wished for his people to have a paradise without conflict.
In the year 784, it was discovered by a miner with twenty years of experience who attempted to dig under Wall Rose to reach Wall Sina that the ground below the Walls was made of the same material as the Wall and that they also seem to extend surrounding human territory underground.
The Outermost Wall:
Wall Maria is the largest and outermost of the three protective walls that encircle human society. Spanning vast territories, Wall Maria was once the boundary of the most expansive and thriving human civilization. It served as the first line of defense against the Titans and separated humanity from the outside world, where Titans still roam freely and cause widespread destruction.
Significance:
Wall Maria's significance cannot be overstated, as its breach by the Colossal Titan in the very first episode sets the entire series into motion. The sudden appearance of this enormous Titan, coupled with the surprise attack, causes a catastrophic breach in Wall Maria, forcing humanity to retreat inward to the next level of defense. This breach marks the beginning of the central conflict, as humanity loses a vast portion of their territory and begins a desperate fight for survival. The fall of Wall Maria becomes a symbol of humanity's vulnerability, setting the stage for the desperate battles that follow.
The Middle Wall:
Wall Rose is the second wall, situated between Wall Maria and Wall Sina. It is not as large as Wall Maria, but it serves as humanity's second line of defense. Wall Rose acts as a fallback, providing a last refuge for the survivors from the outer regions of Wall Maria after its fall. This wall is home to some of the largest remaining cities in human civilization, and it plays a central role in the series.
Significance:
Wall Rose becomes the primary battleground for humanity's struggle against the Titans in the early part of the story. After the breach of Wall Maria, the characters, including Eren, Mikasa, Armin, and other soldiers of the Scout Regiment, fight to protect the civilians who are now confined to Wall Rose. The wall itself faces multiple breaches and threats from the Titans, and the defense of Wall Rose highlights the tension between human ingenuity and the seemingly unstoppable power of the Titans. Wall Rose is also where key revelations begin to unfold, as humanity starts to learn more about the Titans' origins and the secrets of the walls themselves.
The Innermost Wall:
Wall Sina is the innermost and smallest of the three walls, located directly around the central capital, where the royal family and the highest-ranking government officials live. Wall Sina represents the final bastion of humanity’s elite, where the wealthiest and most powerful individuals reside in a highly controlled, isolated society. The inner sanctum of the walls is a place of relative peace and safety, far removed from the hardships faced by those living on the outer walls.
Significance:
Wall Sina's importance lies in its status as the seat of power. It is in this area that the secrets of the walls, the Titans, and the monarchy are hidden. The capital city within Wall Sina is where many political plots unfold, and it is here that the central mysteries of the Attack on Titan story are slowly revealed. The wall’s fortified nature represents the complete separation of the ruling class from the rest of humanity. However, as the story progresses, Wall Sina becomes a focal point for corruption, conspiracy, and the hidden truths about humanity’s origins, including the role of the royal family and their involvement with the Titans. It is also where the final defense is mounted when humanity faces its most intense threats.
Source:
https://attackontitan.fandom.com/wiki/Walls_(Anime)