All the remaining floors were open for tenants. Of the 110 stories in each tower, 8 were set aside as mechanical floors.

Each tower was over 1,350 feet (410 m) high, and occupied about 1 acre (0.40 ha) of the total 16 acres (6.5 ha) of the site's land. One World Trade Center was the North Tower, and Two World Trade Center was the South Tower. The twin towers at 1 and 2 World Trade Center were designed as framed tube structures, giving tenants open floor plans, unobstructed by columns or walls. The project was planned by the Port Authority of New York and New Jersey, which hired architect Minoru Yamasaki. The project was intended to help revitalize Lower Manhattan. The construction of the original World Trade Center was conceived as an urban renewal project and spearheaded by David Rockefeller. The first One World Trade Center under construction in May 1970 The construction of the new building is part of an effort to memorialize and rebuild following the destruction of the original World Trade Center complex. The new World Trade Center complex will eventually include five high-rise office buildings built along Greenwich Street, as well as the National September 11 Memorial & Museum, located just south of One World Trade Center where the original Twin Towers stood. The building has 94 stories, with the top floor numbered 104. On March 26, 2009, the Port Authority of New York and New Jersey (PANYNJ) confirmed that the building would be officially known by its legal name of 'One World Trade Center', rather than its colloquial name of 'Freedom Tower'. The building opened on Novemthe One World Observatory opened on May 29, 2015. Its height in feet is a deliberate reference to the year when the United States Declaration of Independence was signed. On May 10, 2013, the final component of the skyscraper's spire was installed, making the building, including its spire, reach a total height of 1,776 feet (541 m). The tower's steel structure was topped out on August 30, 2012. One World Trade Center became the tallest structure in New York City on April 30, 2012, when it surpassed the height of the Empire State Building. The construction of below-ground utility relocations, footings, and foundations for the new building began on April 27, 2006. It is bounded by West Street to the west, Vesey Street to the north, Fulton Street to the south, and Washington Street to the east. The new skyscraper stands on the northwest corner of the 16-acre (6.5 ha) World Trade Center site, on the site of the original 6 World Trade Center. The supertall structure has the same name as the North Tower of the original World Trade Center, which was destroyed in the terrorist attacks of September 11, 2001.

Designed by David Childs of Skidmore, Owings & Merrill, One World Trade Center is the tallest building in the United States, the tallest building in the Western Hemisphere, and the seventh-tallest in the world. One World Trade Center (also known as One World Trade, One WTC, and formerly Freedom Tower) is the main building of the rebuilt World Trade Center complex in Lower Manhattan, New York City. Hill International, The Louis Berger Group Port Authority of New York and New Jersey b. May 29, 2015 7 years ago ( ) (One World Observatory)

World trade center observatory