The eighteen-story building was constructed by the Fisher Brothers developers in 1960. The Park Cinq shares its Fifth Avenue block with the Sherry Netherland Hotel. The building has eighteen stories and a penthouse. The upper floors offer "sweeping Central Park views."
The year the building opened, the New York Times described it as containing sixty-six "mansions," and described it as being "the world's most luxurious multiple dwelling." Among the luxury details considered remarkable in that era where the presence of telephone outlets in every room and special windows designed to keep out noise. There were also marble bathrooms and parquet floors, but the entire building was in modern style unlike the traditional Renaissance and Georgian styles of older buildings in the neighborhood. The building's dedication was attended by Prince and Princess Serge Belosselsky-Belozersky.
- 'Good' Address Is Vital To Many New Yorkers; Out-of-Towners' View Helpful for Loans, MARYLIN BENDER, New York Times September 11, 1962
- "Geffen Buys Fifth Avenue Co-op for $14 Million". The New York Times. Retrieved 2 August 2015.
- CO-OP 'MANSIONS' TO BE OPEN SOON; 5th Ave. Building Will Have Tenants This Month, SANKA KNOX, August 15, 1963, New York Times.
- Denise Rich's Daughter Buys Downstairs From Mom at 785 Fifth for $3.9 M, Max Abelson, August 21, 2007, New York Observer,  Archived June 10, 2010, at the Wayback Machine