Lima is the capital and the largest city of Peru. It is located in the valleys of the Chillón, Rímac and Lurín rivers, in the central part of the country, on a desert coast overlooking the Pacific Ocean. Together with the seaport of Callao, it forms a contiguous urban area known as the Lima Metropolitan Area. With a population approaching 9 million, Lima is the fifth largest city in Latin America, behind Mexico City, São Paulo, Buenos Aires and Rio de Janeiro. Lima is home to one of the largest financial hubs in Latin America. It has been defined as a beta world city by GaWC international ranking.