The Hardenbergh/Rhinelander Historic District consists of six rowhouses and one “French Flats” building constructed in 1888-89 for the estate of William C. Rhinelander to the Northern Renaissance Revival style designs of architect Henry J. Hardenbergh.Located at the northwest corner of Lexington Avenue and East 89th Street, these buildings are characteristic of the residential development of the Carnegie Hill-Yorkville area that had been spurred by transportation and street improvements in the late nineteenth century. The Rhinelanders, a family prominently associated with real estate in Manhattan, were significant in that development, and through the Rhinelander Real Estate Co., controlled the properties in this historic district until 1948.Clad in red brick, brownstone and red terra cotta, the six houses form a picturesque yet symmetrical composition featuring a variety of window entrance enframements and a lively roofline composed of prominent pediments and modillioned cornices with pierced parapets and finials. The flats building located behind the houses and facing 89th Street, is clad in similar materials, has a complementary architectural vocabulary, and is dominated by a broken pediment/cornice surmounted by a pedimented window.

Distinguished by their common design history and ownership by the Rhinelander family for sixty years, the buildings have survived as an enclave, surrounded mostly by later apartment buildings. They are, furthermore, among the most significant surviving reminders of the Rhinelanders residential development in the neighborhood.

The houses have also been associated with a number of other prominent owner-residents, among them artist Andy Warhol and the Fertility Institute of New York. Summary from The Hardenbergh/Rhinelander Historic District Designation Report, New York City Landmarks Preservation Commission, 1998.