A Megalopolis is a chain of adjacent metropolitan areas or single city with a population of ten million or more. There are two possible sources for the term megalopolis. Either it comes from the actual city of Megalopolis in the Greek province of Achaea or the literal meaning of the word itself, which is Great City. The city by this name was given the title for irony's sake as the city was one of the smallest municipalities in the Roman Empire. Whatever the origin, the term Megalopolis has entered international vernacular as a description for a great urban area.