The National September 11 Memorial & Museum (branded as 9/11 Memorial and 9/11 Memorial Museum) is the principal memorial and museum commemorating the September 11 attacks of 2001, which killed nearly 3,000 people, and the World Trade Center bombing of 1993, which killed six. The memorial is located at the World Trade Center site, on the former location of the Twin Towers, which were destroyed during the attacks. The World Trade Center Memorial Foundation was renamed the National September 11 Memorial & Museum at the World Trade Center in 2007.

Dancers Amy Hadley and Bethany Kingsley-Garner from the Scottish Ballet wait backstage during the dress rehearsal of the current production of “Sleeping Beauty” at the Theatre Royal on December 16, 2011 in Glasgow, Scotland. (Photo by Jeff J Mitchell/Getty Images)

A member of Iraqi rapid response forces fires a rocket launcher during a battle with Islamic State militants in the district of Yarimja in southern Mosul, Iraq, January 18, 2017. (Photo by Alaa Al-Marjani/Reuters)

An aspiring Catholic priest Jose Luis Guerra, a member of Raza Nueva in Christ, a project of the archdiocese of Monterrey, and other missionaries hand out a Bible to Angel Castillo, who wants to become a missionary with Raza Nueva, in the municipality of Garcia, outskirts of Monterrey, Mexico, July 12, 2016. In the troubled fringes of the northern Mexican city of Monterrey, an aspiring priest is using his faith to reach out to young gang members and at-risk youth, and bring them into his “Gang of Christ”. (Photo by Daniel Becerril/Reuters)

Gers, traditional Mongolian tents, are seen on a hill in an area known as a ger district in Ulan Bator June 26, 2013. Approximately 60 percent of the population of Ulan Bator live in settlements known as ger districts and in many cases residents have limited access to basic services such as water and sanitation. According to a 2010 National Population Center census, every year between thirty and forty thousand people migrate from the countryside to the capital Ulan Bator. Ger districts in the city have been expanding rapidly in recent years. Mongolia is the world's least densely populated country, with 2.8 million people spread across an area around three times the size of France. (Photo by Carlos Barria/Reuters)

Potters colour earthen lamps at a workshop ahead of the Hindu festival of Diwali in Amritsar October 15, 2014. Earthen lamps are sold in large numbers during Diwali, the annual Hindu festival of lights, as people use them to decorate their homes. (Photo by Munish Sharma/Reuters)

A Femen activist, Sarah Constantin, is hanged from a noose-like rope from a Paris bridge to call attention to the large number of executions in Iran as she stages a protest against visiting Iranian President Hassan Rouhani in Paris, Thursday, January 28, 2016. A near-naked woman hanging from a noose-like rope from a Paris bridge has sent a message to visiting Iranian President Hassan Rouhani. (Photo by Zacharie Scheurer/AP Photo)