The six-hectare (16-acre) work site that has emerged from the rubble of the twin towers has come to symbolise the dreadful events of September 11, 2001 when almost 3,000 people lost their lives. The 1,350ft (411m) World Trade Centre towers were the tallest buildings in New York and symbols of the city's skyline. Millions now come to pay tribute at the site and witness the devastation from one of the viewing sites. In April 2003, the Lower Manhattan Development Corporation launched a worldwide competition to design a memorial at the World Trade Center site to honour the victims of September 11. The LMDC received 5,201 memorial design submissions from 63 nations and 49 states making this the largest design competition in history. In January 2004 'Reflecting Absence' by Michael Arad and Peter Walker was unveiled as the design for the World Trade Center Memorial, and will feature a landscaped civic plaza with two massive voids aligned with the footprints where the twin towers once stood. Currently the perimeter of Ground Zero is accessible to the public. The Tribute Center, across from Ground Zero, offers tours around the perimeter, and provides visitors with an accurate account of what the community endured during the attacks. The Memorial and Museum are scheduled to open to visitors in September 2012.

Address: Tribute WTC Visitor Center: 120 Liberty Street

Website: www.national911memorial.org

Telephone: (212) 393 9160

Transport: Take the subway to Fulton Street, Broadway-Nassau Street or Cortlandt Street. Walk to Church and Liberty Streets and follow signs

Opening times: Preview site: Monday to Sunday 10am-8pm. Closes 6pm in winter.

Admission: Free