The Alta-Plana website is made to archive the world of Les Cites Obscures on the Internet. It hosts the most comprehensive dictionary of all topics related to these Obscure Cities and it authors Francois Schuiten and Benoit Peeters. The original dictionary was made late 90s by Sylvain St.Pierre. It was turned into the current dictionary in 2011 by Joseph le Perdriel.
These sites all relate to the stories, art and study of Schuiten and Peeters' Les Cités Obscures.