Post Office Square in Boston, Massachusetts, is a square located in the financial district at the intersection of Milk, Congress, Pearl and Water Streets. It was named in 1874 after the United States Post Office and Sub-Treasury which fronted it, now replaced by the John W. McCormack Post Office and Courthouse.
The square is almost entirely occupied by a privately owned and managed but publicly accessible park, Norman B. Leventhal Park, named for the Boston building manager and designer who designed it. It sits above a parking garage, named "The Garage at Post Office Square." The garage descends to 80 feet below the surface, at the time one of the deepest points of excavation in the city.
Wikipedia https://en.wikipedia.org/wiki/Post_Office_Square,_Boston
Address 130 Congress St, Boston 02110, United States
Coordinates 42°21'22.65" N -71°3'20.353" E