Manhattan has been described as the cultural, financial, media, and entertainment capital of the world, and the borough hosts the United Nations Headquarters. Anchored by Wall Street in the Financial District of Lower Manhattan, New York City has been called both the most economically powerful city and the leading financial center of the world, and Manhattan is home to the world's two largest stock exchanges by total market capitalization: the New York Stock Exchange and NASDAQ. Many multinational media conglomerates are based in Manhattan, and the borough has been the setting for numerous books, films, and television shows. Manhattan real estate has since become among the most expensive in the world, with the value of Manhattan Island, including real estate, estimated to exceed US$3 trillion in 2013; median residential property sale prices in Manhattan approximated US as of 2018, with Fifth Avenue in Midtown Manhattan commanding the highest retail rents in the world, at US per year in 2017.