What is the valley of the ashes and and why is it symbolic?

In my opinion, it represents the "real world," the world that isn't totally airbrushed the way Gatsby's and Daisy's houses are. The Valley of Ashes is basically this big grey dumping ground, and it's where the only poor characters in the novel live, Myrtle and George Wilson. These two, like their surroundings, are real and not fake like the world Gatsby made for himself. The Valley of Ashes is also watched over by the billboard of Doctor Eckleburg (spelling?), which represents the eyes of god, so basically even though the Valley is gross and dirty, it represents sort of the honesty and goodness of the hard-working poor.

This is just my opinion.