|Elevation||348 ft (106 m)|
|Prominence||348.0 ft (106.1 m)|
|Location||Roslyn, New York,
|Topo map||USGS Sea Cliff|
Harbor Hill was a large Long Island mansion built from 1899-1902 in Roslyn, New York, commissioned by Clarence Hungerford Mackay. It was designed by McKim, Mead, and White, with Stanford White supervising the project. It was the largest home he ever designed.
Clarence Mackay (1874–1938) was the son of Comstock Lode magnate John William Mackay, and inherited much of an estimated $500 million fortune upon his father's death in 1902 (approximately $13 billion in 2012 dollars). White collaborated closely with Clarence Mackay's wife, Katharine Duer Mackay (1880–1930), and with her approval, based the main façade of Harbor Hill upon that of François Mansart's Château de Maisons of 1642, using a mix of other influences to finish the overall design.
Built at great expense and furnished lavishly (at least three different decorating firms were employed), the home originally sat on 688 acres (2.78 km2) and enjoyed views across Roslyn Harbor to Long Island Sound. Formal terraces and gardens were finished by Guy Lowell.
On June 13, 1927, Charles Lindbergh, accompanied by his mother and the Mayor of New York, was Clarence MacKay's guest of honor at a banquet and dance the night of Lindbergh's ticker-tape parade on 5th Avenue.
After Harbor Hill was dynamited in 1947, a fountain with four equestrian statues, designed by Henri-Léon Gréber, was moved to Kansas City, Missouri where it has since been on public display adjacent to the Country Club Plaza.
Harbor Hill, the site of the former mansion, is the highest point in Nassau County, New York, at 348 feet. Whether Harbor Hill or 401-foot Jayne's Hill to the east was the highest point on Long Island was a point of some debate in the 19th century, with Harbor Hill often thought to be the highest summit.
Much of the estate, including the site of the main building, has been covered with a modern housing development. However, three remaining buildings from the Harbor Hill estate were listed on the National Register of Historic Places in 1991: Mackay Estate Dairyman's Cottage, Mackay Estate Gate Lodge, and Mackay Estate Water Tower.
- List of Gilded Age mansions
- "Harbor Hill: Portrait of a House" by Richard Guy Wilson.
- Bill Bryson, "One Summer: America, 1927" (Doubleday 1913)
- USGS GNIS Detail, Harbor Hill
- "Highest Point on Long Island". Brooklyn Daily Eagle. June 7, 1901. (reporting that Jayne's Hill is indeed taller)
- "Walt. Funnel Stands Up For Jayne's Hill". The Long Islander. Dec 15, 1938. ("There was really a bit of blood pressure on the subject as advocates pressed their arguments...")
- "Questions Answered". Brooklyn Daily Eagle. October 9, 1887. (listing Harbor Hill at 384 feet, and Jayne's Hill at 383)
- Brooklyn Daily Eagle Almanac, 1890, p. 85 (Harbor Hill 384; Jayne's Hill 383)
- National Park Service (2009-03-13). "National Register Information System". National Register of Historic Places. National Park Service.