The description of the "valley of ashes" opens Chapter 2. On a literal level, what is the valley of ashes? What might it represent on a symbolic level?

Literally, the Valley of Ashes is a massive trash dump. The rotting valley represents the rotting American dream. Tom, Daisy, and Jordan, with their endless socials and superficial lives represent how material excess rots their very souls. Their lives, like the valley, are hollow. As time goes on the valley gets ranker as do the lives of many characters in the novel. Self-centered individuals litter the story with meaningless "trash", much like the valley itself.