Lower Manhattan is the southernmost part of the island of Manhattan, the main island and center of business and government of the City of New York. It is generally defined as the area delineated on the north by Chambers Street, on the west by the North River (Hudson River), on the east by the East River, and on the south by Battery Park and New York Harbor (also known as Upper New York Bay). Lower Manhattan includes City Hall, the Municipal Building, the Financial District and the site of the World Trade Center.

It is the fourth largest central business district in the United States, after Midtown Manhattan, Chicago's Loop, and Washington D.C. The neighborhood was previously the third largest CBD [1]. Lower Manhattan's fall to fourth place can be attributed by the district's loss of the World Trade Center, which contributed over 16 million square feet of office space to the area. The square footage lost in the September 11, 2001 terrorist attacks was equivalent to the office space in the entire city of Cincinnati in 2001. It is expected that Downtown will regain its third place ranking after the reconstruction of the World Trade Center, which is expected to yield close to the original center's square footage of rentable commercial space, and the construction of financial firm Goldman Sachs' new headquarters.