In The Great Gatsby, describe the peculiar land formations resulting in East and West Eggs. What is the significance of their differences?

East Egg and West Egg are somewhat odd, egg-shaped land formations on Long Island.  Nick says that they are about twenty miles away from New York City and are "identical in contour and separated only by a courtesy bay [...]."  East Egg is further away from the city and occupied by people like Tom and Daisy Buchanan and their "white palaces"; it was established first, before West Egg, as the spot where the people with 'old money' live.  West Egg was inhabited a bit later, and it is where people like Gatsby live; Gatsby has 'new money,' money that he has earned rather than money that he has inherited from a wealthy family, like the Buchanans.  West Egg is the less prestigious of the Eggs, just as new money (recently earned) carries less prestige than old money (inherited).  It is notable that these two groups are not only differentiated by their value and influence in society but also by their geography.