World Trade Center
The new One World Trade Center began construction in 2006; in April 2012 it surpassed the Empire State Building to become the city's tallest. Upon its topping out in May 2013, the One World Trade Center surpassed the Willis Tower to become the tallest building in the United States. One World Trade Center is part of the redevelopment of the World Trade Center, which also includes the 3 World Trade Center, the 4 World Trade Center, the 7 World Trade Center, the proposed 900-foot (274 m) 5 World Trade Center, and one partly-constructed on hold building: the 2 World Trade Center.