Mallory Square is a plaza located in the city of Key West, Florida, United States. It is located on the waterfront in Key West's historic Old Town, adjacent to the cruise ship port. It is located just west of the northern end of Duval Street, facing the Gulf of Mexico. It runs the entire length of Wall Street. Adjacent to the square are the Key West Shipwreck Historeum Museum and the Old Post Office and Customshouse.