Most expensive apartment in US listed for $100m
New York, July 31 : You can be the proud owner of the most-expensive apartment in the United States — a triplex, 
wrap-around penthouse on W. 56th Street – if you have 100 million dollars to spare.
Raphael De Niro, the son of actor Robert De Niro, has the exclusive listing on the 73rd through 76th floor aerie atop CitySpire — the deluxe apartment in the sky, which is owned by Long Island real estate developer Steven Klar.
The space includes inlaid marble floors.