2 World Trade Center has had a long and surprisingly complicated development history. It was originally designed by Foster + Partners, before the Bjarke Ingels Group was hired for the gig – but then Foster + Partners was ultimately brought back for the current iteration.

The wait was probably worth it, given the importance of the building. In a city packed with cookie-cutter glass office towers, 2 World Trade Center will be something of a head-turner with its stepped design punctuated by multiple terraces and greenery, the latter also providing continuity with the many trees at ground level.

Its interior will consist of around 2 million sq ft (almost 186,000 sq m) of office space, spread over 55 floors, and will serve as the new global headquarters for American Express. It will have the capacity to host around 10,000 staff.

"As we approach the 25th anniversary of 9/11, starting construction of 2 World Trade Center is not just a significant step forward for Lower Manhattan, but it is also an inspiring demonstration of New York's strength and resilience in the face of adversity," says Kathryn Garcia, Executive Director of Port Authority, following the groundbreaking ceremony, which included several politicians and high-ranking officials. "This investment by American Express in a new, state-of-the-art tower advances our shared goal of completing the restoration of the World Trade Center as a site that supports commerce, remembrance, culture, community, transit and tourism for all the world to see."

Though the groundbreaking ceremony has only taken place earlier this month and construction is now ramping up, initial groundwork on the project actually began back in 2008, with its massive foundations finished in 2013. It's expected to be completed in 2031, and is being developed by Silverstein Properties.

The project, which is the final commercial tower planned for the World Trade Center redevelopment, joins the adjacent One World Trade Center, which is the USA's tallest skyscraper, the 3 World Trade Center office tower, and the only residential building on the site, 5 World Trade Center.