The lab where Koudo does all types of experiments on people that he's captured or people that have offered themselves to him in the pursuit of power. It's an extremely dangerous place, with monsters and traps lurking around every corner and corridor.
The most dangerous Armory in all of Aurnion. It gives the most powerful Soul weapons and other weapons out, but it's a dangerous journey here and if anyone does make it, the leader of the Nostra himself battles you to see if you're worth of the weapon you're questing for.
La Costra members fill come here for missions. The tougher the mission, the higher your rank has to be to complete it. Only Shuhan, Underbosses, and Capos, can post missions here, but any member of La Costra Nostra can participate in the mission.