1. Henry Cook Mansion
The Henry Cook Mansion is often though to be a part of the Payne Whitney House, since they are adjacent structures that have very similar styled, but they are in fact two separate residences. Henry Cook, a banker and railroad tycoon, commissioned White to build him a townhouse on the illustrious Fifth Avenue. White designed an Italian Renaissance Palazzo style home with more than 15,000 square feet of living space, but neither her nor Cook would live to see it complete. A year after Cook died, leaving the unfinished home to his daughters, White was murdered on the roof of Madison Square Garden. The townhouse was complete in 1907.
The property caused a stir when it was put up for sale in 2009 for a whopping $49 million and eventually sold for $42 million. The residence faces Central Park and has retained many of its original features, including moldings, fireplaces, leaded-glass windows, and the original floor plan.