A small area sealed by the heavy metal door is equipped with many sensors and cameras. This heavy door is created from the bones of the monsters, and the hardest metal found in this world. No hunter can destroy this door, not even a nuclear bomb can put a scratch. The only way to enter inside is to swipe your Hunter Identity Card (HIC).
Only the hunters from the Hunter Association can enter this place, if hunters from another guild tried to enter, the door won't open for them. Because, every guild, and organization have their own dungeon that generates income for them. And every dungeon has its specific card requirement.
Even if the dungeon is dangerous, instead of co-operating to destroy this dungeon, human has even separated their own dungeon and is doing business. If one day, all the dungeon break out, then the human is destined to be extinct, and the sole reason will be human stupidity.
Ding!
