The Sky Library has been in the skies since ancient times. It watches over the entire world, governing all its wisdom. It is surrounded by a barrier that makes it invisible to the naked eye. It wards off pillagers, since there are some incredible ancient weapons hidden in there. Two Magic King Weapons are sealed away in the sky library.
Partoling Laser Beams
They fire powerful laser attacks at thieves. The lasers are programmed to agitate the magic power inside the target, and in the worse case scenarios they'll end up destroying themselves. They are also able to control people.
Magic Lift 
The elevator that goes back to the surface. It is located at the center of the ruins.