Lower Manhattan is defined most commonly as the area delineated on the north by 14th Street , on the west by the Hudson River , on the east by the East River , and on the south by New York Harbor ( also known as Upper New York Bay ) .
Lower Manhattan or `` downtown '' is defined most commonly as the area delineated on the north by 14th Street , on the west by the Hudson River , on the east by the East River , and on the south by New York Harbor ( also known as Upper New York Bay ) .