A megacity is an urban area housing 10 or more million inhabitants. They are often the primary nodes for investment in a country and feature the most affluent households. Some of the first megacities popped up in the developed world, with New York being the first in the 1950s, but was soon overtaken by the fast-rising Tokyo. Megacities offer wealth, social diversity, economic growth and innovation. They attract the ambitious in search of jobs, business ventures and education.