Windows on the World was an complex of venues at the top floors ( 106th and 107th ) of the North Tower of the World Trade Center and it included Windows on the World , a smaller restaurant which was called Wild Blue , and a bar which was called The Greatest Bar on Earth . Windows on the World was a complex of venues at the top floors ( 106th and 107th ) of the North Tower of the World Trade Center in Lower Manhattan that included a restaurant , Windows on the World , a smaller restaurant called Wild Blue , and a bar called The Greatest Bar on Earth , as well as rooms for private functions .