The power filled the world like air and ordinary people (magicians included as well) could not feel it. Only specially trained magicians or Feng Shui masters could see the force. However, there was no such energy in the four buildings before Index.

Though the power of the world was normally undetectable like basic air, if a vacuum formed, breathing became impossible. Similarly, Index felt an incomparable strangeness.

It was like some tower of death was sliced into cubes, becoming the largest tombstone in the world. It was much too extreme, even if for the sake of trapping mana inside.

[...]

However, the magic tower differed. It was like a city of stone and steel formed after cutting down a forest through forced methods. It was an ugly representation of urbanization.

[...]

“This isn’t a boundary preventing enemies from invading but a boundary to prevent escape. Hm… It’s like an Egyptian pyramid…” muttered the white nun and walked through the automatic doors.


Toaru Majutsu no Index vol.2 ch.3 pt.1