The Floating City
From Drunkapedia
A very old city that has been mostly lost in portal space making it dangerous for anyone wishing to stay for long periods. It predates the Empyreans who at one point lived there and attempted to tame the unstable portal magic.
There are no stable portals to The Floating City. It is, for the most part, only accessible via a randomly appearing landscape portal, similar to the Humming Crystal Portal. It is however possible for a portal to the City to appear at locations where there is a randomly generated portal (for example, northern point).
The Famous early explorer of Dereth and friend of Elysa Strathelar Alatar Locke once traversed parts of the city and left behind his notes on each section.
A Stained Book