The World Trade Center (sometimes informally the WTC or Twin Towers ) was a seven-building complex in Lower Manhattan (New York City) that was destroyed in the September 11 attacks.

In the late 1950s, David Rockefeller suggested that the Port Authority of New York and New Jersey build the World Trade Center, to help stimulate urban renewal in Lower Manhattan. In gaining approval for the project in the early 1960s, the Port Authority agreed to take over the Hudson & Manhattan Railroad, which became the Port Authority Trans-Hudson (PATH). The site selected was the location of the decrepit Hudson Terminal building, along with the surrounding Radio Row neighborhood.

The World Trade Center was designed by Minoru Yamasaki, with twin 110-story towers, using a tube-frame structural design, which was innovative at the time. The elevator system in the towers utilized large-capacity express elevators, which went to sky lobbies, along with local elevators serving individual floors. Groundbreaking for the World Trade Center took place on August 5, 1966. The North Tower was completed in December 1970, while the South Tower was finished in July 1971. Construction of the World Trade Center involved excavating a large amount of material, which was used to create Battery Park City on the west side of Lower Manhattan.

The complex, located in the heart of New York City's downtown financial district, contained 13.4 million square feet (1.24 million m²) of office space. An observation deck was located atop the South Tower, while the Windows on the World restaurant was located at the top of the North Tower. Other World Trade Center buildings included the Marriott World Trade Center, 6 World Trade Center, which housed the United States Customs, and 7 World Trade Center, which was built in the 1980s. The World Trade Center was beset by a fire on February 13, 1975 and a bombing on February 26, 1993. In 1998, the Port Authority decided to privatize the World Trade Center, leasing the buildings to a private company to manage, and awarded the lease to Silverstein Properties in July 2001.

On the morning of September 11, 2001, al-Qaeda affiliated hijackers flew two Boeing 767 jets into each tower, in a coordinated suicide attack. After burning for 59 minutes, the South Tower collapsed, followed a half-hour later by the North Tower, with the attacks on World Trade Center resulting in 2,750 deaths. The process of cleanup and recovery at the World Trade Center site took eight months. The first new building at the site was 7 World Trade Center, which opened in May 2006. The Lower Manhattan Development Corporation (LMDC), established in November 2001 to oversee the rebuilding process, organized competitions to select a site plan and memorial design. Memory Foundations, design by Daniel Libeskind, was selected as the master plan, which includes the 1,776 ft Freedom Tower, three office towers along Church Street, a memorial (designed by Michael Arad), and calls for Greenwich Street to be restored.