The Kadath Travel Guide. In French only, but profusely illustrated.
Translated blurb:
“With this new book published by Mnemos, you will begin the most fantastic dream quest for the first time since HP Lovecraft, you will survey your own risk the unknown streets of the city of Kadath. Four authors and illustrator have explored Kadath for you. On the trail of Randolph Carter, between beauty and terror, demons and wonders, you explore the famous city of the Lands of Dream, the capital of forgotten gods and cursed ones.”