The current front line is the 74th floor. With these conditions, the huge castle had been steadily conquered for two years. However, once someone made a breakthrough and arrived at a city of the upper floor, the «Teleport Gates» there and of every cities in the lower floors would be connected making it possible for anyone to move freely through these levels. Only one stairway linked each floor to another, and the stairways existed in dungeons where large numbers of monsters roamed so discovering and getting through was no easy matter. Inside, there were a couple of large cities along with countless small scale towns and villages, forests and plains, and even lakes.
It was impossible to even guess how much data it consisted of. Above, there were 100 floors stacking straight upwards its sheer size was unbelievable. It took a vagarious group of craftsmen one month to survey the place the diameter of the base floor was about 10 kilometers - large enough to fit the entirety of Setagaya-ku within. A huge castle made of stone and steel floating in an endless sky.
