The 25-ton Koenig Sphere was officially placed on view Wednesday at the new Liberty Park overlooking the 9/11 memorial.
The Port Authority of New York and New Jersey last year approved plans to move the sculpture from its temporary place in Battery Park at Manhattan's southern tip.
The sphere once stood between the trade center's two towers.
The late German artist Fritz Koenig created the work commissioned by the Port Authority, which later lost 84 employees.
Its eternal flame honors the more than 2,700 people who died at the trade center in 2001.