The Dungeon is seemingly alive, spawning monsters from walls and ceilings and repairing itself on its own. While the upper floors can be soloed or done with a pair, starting from the middle floors one must create a party or risk death.
The dungeon is vast with the floors becoming progressive larger the deeper it gets. It takes at least five days for a party to reach the 50th floor.
The entrance to the Dungeon is on the first underground floor of Babel. In the center of the room is a ten meter long hole that leads straight into the Dungeon. Within the circular room are multiple columns at equal intervals and above is a beautiful azure painting of the sky that resembles the real sky. Along the circle are gentle stairs that spiral down into the Dungeon.
The walls are light blue colored, and the monsters that appear are Goblins or Kobolds. There is also a wide hallway on the 1st Floor known as the Beginning Road.