The National September 11 Memorial and Museum has opened at Ground Zero to visitors and families of victims who were killed in the 9/11 attacks in New York and Washington.
Built on the bedrock of Manhattan, where the foundations of the old Twin Towers stood, the museum gives a visual reminder of the scale of the horror that happened there on September 11, 2001.
The museum has opened its doors in a neighbourhood that some predicted would never recover after Al-Qaeda terrorists hijacked four commercial jets, killing nearly 3,000 people.
Among the first visitors to the museum will be victims' family members and others involved in its creation.
Some of the 10,000 items on display at the museum include the Last Column, the 'Survivor's Stairs' and the two salvaged tridents from the World Trade Center.