The Twin Towers, officially part of the World Trade Center complex in Lower Manhattan, were primarily used as office buildings. They housed a large number of businesses from around the world involved mainly in trade, finance, and commerce. Besides office space for these companies, the towers also hosted Port Authority offices, art studios, markets, and even a restaurant called Windows on the World. Their main purpose was to serve as a hub for international trade and business, making them centers for trading and commerce globally. They offered almost 10 million square feet of rentable office space, serving as a symbol of economic opportunity and prosperity in New York City and the United States in general from their completion in the early 1970s until their destruction in 2001.
