An underground cavern that has been maintained from the days of the Imperator. It has entrances from every region, though no one knows why this is so. This location contains one area. It is missable. To gain access talk to the Geography-Savvy Knight found in Melphina's guild. You get the key required for opening the door to access the second part via the quest The Disappearing Knights (or by simply talking to Roberto, if the quest is no longer available). Interconnects with The Fifth Path through [[The Final Fortress#Fourth <-> Fifth|The Final Fortress]].