"The Sphere," by Fritz Koenig, was originally designed as a work of art that was situated between the Twin Towers in Manhattan in 1971.
The work was inspired by the Kaaba at The Grand Mosque of Mecca and was meant to symbolize peaceful world trade. After the September 11th attack in 2001, the sphere miraculously remained mostly intact, with only minor damage.
After the attacks the sculpture was stored at JFK Airport. Koenig paired up with director Percy Adlon to create a film entitled Koenigs Kugel explaining the creation and history of the sculpture. On March 11th, 2001 The Sphere was relocated to Battery Park and is now recognized as a monument of the victims of 9/11 and is meant to represent America's strength and resiliency.
In 2012, there was discussion of moving the monument once again for maintenance reasons, however its fate is still unclear.