Although as decadent, fast and urban in 1922 as it is in the modern context, New York City in Gatsby is a secondary setting. It is the place where businessmen meet and where Nick works. It's also where the rich go when bored to entertain themselves with shopping, affairs or simple hedonism.
New York City also represents a version of the American Dream. It is a place of enormous possibility, wealth, hope – and corruption.
The anithesis of life in East and West Egg, the Valley consists of smoky air, piles of ashes, railroad lines and a few scattered businesses; a buffer between the wealth of Nassau and Suffolk Counties and the densely populated Brooklyn and Queens areas located just across the East River from New York City.
It is also where Daisy and Gatsby meet in 1917 when he is a soldier and she a debutante helping out with the Red Cross.