In The Great Gatsby, what are the ash heaps?

This is an interesting question. There is quite a bit of confusion as to what the valley of ashes is actually made up of. The text does not make it easy to find this out for sure, since its reference is quite ambiguous.

About half way between West Egg and New York the motor road hastily joins the railroad and runs beside it for a quarter of a mile, so as to shrink away from a certain desolate area of land. This is a valley of ashes—a fantastic farm where ashes grow like wheat into ridges and hills and grotesque gardens; where ashes take the forms of houses and chimneys and rising smoke and, finally, with a transcendent effort, of men who move dimly and already crumbling through the powdery air. Occasionally a line of gray cars crawls along an invisible track, gives out a ghastly creak, and comes to rest, and immediately the ash-gray men swarm up with leaden spades and stir up an impenetrable cloud, which screens their obscure operations from your sight. But above the gray land and the spasms of bleak dust which drift endlessly over it . . .

There is no direct mention of ash heaps in the extract, but references such as 'fantastic farm,' 'ashes grow like wheat,' and 'grotesque gardens' paint a picture of something growing there—ash trees. However, this definition is contradicted by words and descriptions such as 'desolate' and 'ashes take the forms of houses and chimneys and rising smoke,' which do not suggest growth, but ruin and decay.

The word 'desolate' punctuates the fact that this is a barren area in which nothing grows, so there are no trees. All that there is is the ever-swirling dust which permeates and envelops everything within its reach so that it, too, looks like ash.

It is probable that F. Scott Fitzgerald purposely juxtaposed these descriptions to create an ambiguity, the purpose of which is to accentuate the destructive nature of the so-called 'American Dream.' What had once been an idealistic notion has been turned into dust. It is, indeed, a very clever play on the word 'ashes' since the trees and the dust, both of which the word refers to, are similar in that they are gray in color and, therefore, dull.

Instead of real trees growing in the valley, the only thing that is actually growing is the ash, the dust, not only because the valley has become a dumping ground for others' waste but that, symbolically, it represents that dreams have turned into dust. The flame of idealistic hope has destroyed itself and is burnt out and, instead of it rising out of its ashes like the phoenix, it remains just that—useless dust. In this sense, then, the valley of ashes is a place covered in heaps of ash. It is, literally and figuratively, a dumping ground.

Those who live close to or around this valley are people who have lost their dreams. They live ordinary, mundane and anxious lives. They struggle to survive. They are the ones who had hope but who have now become hopeless. Such people are the tragic George and Myrtle Wilson, who eke out an existence running a nondescript garage.

The extract further suggests that everything within the valley is prone to come to a stop, as do Myrtle and George Wilson. Their miserable lives are juxtaposed with the wealthy, privileged and careless lives of the rich, such as Tom and Daisy Buchanan.