The silvery, 1,776-foot skyscraper that rose from the ashes of 9/11 to become a symbol of American resilience opened for business Monday, as 175 employees of the magazine publishing giant Conde Nast settled into their first day of work in their new offices.
Click to read about the World Trade Center re-opening 13 years after 9/11.
Scroll below to learn more about the new skyscraper at the former Twin Towers site.