Thanks to Erik Larson's 2003 bestseller, "The Devil in the White City," yet another generation is fascinated by the 1893 Chicago World's Fair: Columbian Exposition. Despite its enduring - in itself somewhat surprising - popularity, little remains of this by all accounts stunning little temporary city. One survivor serves as the entrance and gift shop to The Pabst Mansion, 2000 W. Wisconsin Ave., and it is in increasingly desperate condition.