3. 11 Madison Avenue: $2.29 Billion

Located next to Madison Square Park, another one of New York City’s iconic parks, the Art Deco 11 Madison Avenue was sold for $2.29 billion in 2015, making it the second highest sale price for an office building in the United States. Whereas the General Motors Building was purchased via a joint venture between three companies, 11 Madison Avenue was bought by one company: SL Green Realty Corp., of the largest real estate companies in New YOrk City.

The landmarked building, designed by Harvey Wiley Corbett and Dan Everett Waid, was built as part of the Metropolitan Life company complex, along with the recognizable clocktower at 1 Madison Avenue. Both buildings are connected via a skybridge. 11 Madison Avenue was originally planned to be 100 stories, which would have been the tallest in the world. The completed structure, which would have been the base of the building, has the foundational support to reach 100 stories. Today, 11 Madison Avenue houses the headquarters of Credit Suisse, Sony Corporation, the restaurant 11 Madison Park, and other businesses.