City of Greyhawk [available again]

Granted its 2e, but still  good to be back. 

From the description:

Available now in print on demand formats:
The City of Greyhawk (2e)

From the high towers of its grand universities to the rancid alleys of its darkest slums, the City of Greyhawk awaits you. Center of magic and learning in the Flanaess, Greyhawk is also the home of powerful thieves, mighty warriors, traitorous ambassadors, and honest craftsmen.
They all await you within the pages of this information-packed boxed set.

You get four full-size, full-color maps, each depicting a different aspect of the Greyhawk campaign. Two 96-page books give you a detailed overview of the city and a closer look at its more influential citizens - and its more notorious criminals.