Location from Attack on Titan by Hajime Isayama
The outermost of three concentric walls protecting humanity. Fifty meters tall. Breached by the Colossal Titan. Contains hardened Titans within its structure.
Wall Maria is fifty meters of stone and silence. For a hundred years it stood as humanity's first line of defense — an impossibly tall barrier that no Titan could scale. When the Colossal Titan kicked through Shiganshina's gate, a third of humanity's living space was lost overnight. Refugees flooded inward. Food shortages followed. The government sent two hundred thousand civilians on a 'reclamation mission' that was really a cull. Five years later, the Survey Corps retook the wall in a battle that killed almost everyone involved. The wall's deepest secret: it is not made of stone alone. Colossal Titans stand frozen within its structure, shoulder to shoulder, waiting. They were always waiting.
Also known as: Maria, the outer wall, the first wall