The original 1 World Trade Center was one of the Twin Towers of the original World Trade Center complex in New York City. Its construction was begun in 1968 and completed in 1972. It stood at a height of 1,368 feet (417.0 m), and was the tallest building in the world until 1973, when surpassed by the Sears Tower in Chicago. On the 106th and 107th floors of this building were a complex of dining, meeting, and entertainment venues known as Windows on the World. The 106th floor was specifically designed to handle function rooms for private events, large corporate gatherings, and weddings, while the 107th floor housed the main dining rooms and bars. 417 m tall. Wiki link