Siel's blessings.
We've been mapping Tiamat Stronghold, so let me tell you what we know.
The various Legions have Command Centers here: Tahabata to the north, and Laksyaka to the east.
Also in the east is the Military Ward, and finally, to the west, past the Engineering Lab, you'll find the Dredgion Control Center.
Well, we know that Tiamat is in the Dragon Lord's Refuge, which is... up there... somewhere. But we have no idea how to get there. Yet.
There must be a way up from the Tiamat Stronghold. We'll just have to keep looking.
Oh, and if you head to the Military Ward, do take care. There's a prison camp there, and the inmates are out for blood. They don't care whose.