When Attack on Titan’s first season ended with Annie's defeat, fans were in for quite a shock. While trying to escape the main trio and Survey/Scout Corps, Annie climbed the walls using her hardening power to create hand holds for her to use.
As she did, she revealed one of Attack on Titan’s earliest twists, there are Titans hidden in the walls. Now, many manga chapters and anime seasons later, the answer comes in a way that was not expected, but made sense nonetheless.
Disclaimer: This article contains spoilers for Attack on Titan, please read at your own risk.
Attack on Titan's Walls
Paradis Island, the main location of the first two seasons of Attack on Titan, has three giant walls that encase the majority of the land. These walls are Maria, Rose, and Sina/Shenna, named after the three daughters of the ruling Fritz family.
These walls are miles upon miles long, forming large circles around multiple cities and towns.
To give an idea of just how big these walls are, the middle wall, Rose, can take a person days to make a complete circle around it, and the outer wall, Maria, is the largest one yet.
Of course, with such enormous walls, there are a few questions that keen-eyed readers will spot. Namely, to make such gigantic structures, it would take an incredible amount of time and material, and as stated in the opening sequence, the walls have only been up for 100 years.
There is also a distinct lack of mountains, mines, or ore deposits required to build the walls in the first place, and given the setting’s technological level, which aside from 3DM gear, doesn’t appear to be particularly advanced.
So, with all of this information, how were the walls raised?
Why are they there?
In Attack on Titan's final arcs, the truth is revealed. The Wall Titans are the result of Karl Fritz’s last acts as the Founding Titans. Using his command over them, Karl had them become the foundations for the walls, using their hardening abilities to act as support.
The stones on the outside are more of ‘casing,’ with the Wall Titans themselves being the ‘stuffing.’ Karl had the walls made in order to contain his own people, using the ‘tens of millions’ of Titans to make the walls in the first place.
The biology of Titans is quite strange, but one of the few established rules is that uncontrolled Titans need sunlight in order to move, and as they were incased fully, they became dormant and immobile during their 100 year sleep.
The Wall Titans are also part of the Rumbling, which, when the order is given, will unleash the Wall Titans onto the world. Due to their size, each one being around 50 meters tall (for comparison, about half a football field), and being in large numbers, could easily flatten the world.
The reason why the Wall Titans are a threat is because each one possesses the ability to emit large plumes of hot smoke akin to the Colossal Titan, creating smokescreens to hide themselves, or to flash heat water and boil anyone caught in its wake.
Despite their size, each was said to be faster than a galloping horse. Horses in the Attack on Titan universe can run up to 35 kilometers per hour(21.7 miles per hour), most likely due to their long strides and height.
With the Wall Titans, anyone who can command them can either set up an impressive defense, or an attack that could destroy the world.