A huge underground city built by former humanity who fought against the Shadow Angels. It was known as "the last fortress of mankind" and the "legendary capital", but its location is not known. In actuality, it exists underneath the former Alician Empire after the Kingdom of Alicia was destroyed. Because a huge Dragon Vein runs under the ground and is full of energy, it is indispensable for the operation of Aquarion, which consumes an enormous amount of energy. Only Gen Fudo knew of its existence.