Manhattan is the most densely populated of the five boroughs of New York City. The borough is coterminous with New York County, an original county of the U.S. state of New York. The borough consists mostly of Manhattan Island, bounded by the East, Hudson, and Harlem Rivers, but also includes several small adjacent islands and a small area on the mainland. Manhattan has been described as the economic and cultural center of the United States and is home to the United Nations Headquarters. Wall Street, in Lower Manhattan, has been called the financial capital of the world, and is home to the New York Stock Exchange and NASDAQ. As of 2012, Manhattan's cost of living was the highest in the United States, but the borough also suffered the country's most profound level of income inequality. Many multinational media conglomerates are based in the borough.
New York County is the most densely populated county in the United States, more dense than any individual American city. It is one of the most densely populated areas in the world, with a Census-estimated 2013 population of 1,626,159 living in a land area of 22.96 square miles, or about 70,826 residents per square mile.