west egg/et al
Wasn't the point of the valley of ashes was that it was on the outskirts of the big city and it was home to those who just couldn't (or didn't) make it there?
Also, I think there is some nice symbolism in the old billboard in the valley of the ashes that F. Scott writes about. It's an ad for an eye doctor (can't remember the name) and all that's left of the image are the eyes of the doctor. Kind of like the eyes of god.