The square's pocket park is the Queen Elizabeth II September 11th Garden, maintained by the New York City Department of Parks, and has an area of 0.056 acres (0.023 ha) or 2,440 square feet (227 m2).
[1] The square was named for the House of Hanover in 1714 when King George I ascended to the throne.
The Great Fire of New York broke out here on December 16, 1835, decimating much of Lower Manhattan.
[5] Upon the removal of the elevated, a park at Hanover Square was dedicated in November 1951.
Following Queen Elizabeth II's visit of Hanover Square in July 2010, the garden was rededicated as a memorial park for Commonwealth realm citizens who died at the September 11 attacks in May 2012.