Also known as the National September 11 Memorial and Museum, they commemorate the terrorists attacks World Trade Centre on September 11, 2001, which killed almost 3,000 victims, as well as the bombing of the World Trade Centre in 1993 that killed six people. The memorial was designed by Israeli architect Michael Arad and San-Francisco-based landscape architect Pater Walker. The memorial consisted of a forest of trees with two large recessed square-pools with waterfalls in the centre, where the twin towers used to stand, along with footprints of the Twin Towers. The park is at street level and above the Memorial Museum, and the names of all the victims (including those on the airplanes and attack on the Pentagon) are inscribed on the parapets of the surrounding waterfalls. The names were arranged accordingly by an algorithm of “meaningful adjacencies” based in relationships to proximity at the time of the attacks, company or organisation affiliations. Families were constantly consulted and advised.

The underground museum was designed by Davis Brody Bond (entrance is on street level next to the pools). It exhibits around 23,000 images, 10,300 artifacts, almost 2,000 oral histories of the victims, mostly provided by friends and families, and over 500 hours of videos. It also has artifacts from the attacks, including steel from the two towers, such as the final steel and the last piece of steel to leave “Ground Zero” in May 2002.

One World Trade Centre, or Freedom Tower, is the main building of the rebuilt World Trade Centre, bounded by the streets of West, Vesey, Fulton and Washington. It stands on the sight of what used to be 6 World Trade Centre, which was also destroyed by the terrorist attacks. Construction started in April 2006, completed in July 2013, and opened in May 2015.