2. William K. Vanderbilt Mansion at 660 Fifth Avenue: Demolished

Richard Morris Hunt, the architect commissioned to design a home for William K. Vanderbilt and his ambitious wife Alva, “knew his new young clients very well,” writes Arthur T. Vanderbilt II in Fortune’s Children, “and he understood the function of architecture as a reflection of ambition. He sensed that Alva wasn’t interested in another home. She wanted a weapon: a house she could use as a battering ram to crash through the gates of society.” Alva’s home needed to stand out against all the other 5th Avenue mansions. Alva crashed through the gates of society in the spring of 1883 with her “Fancy Dress Ball.” Until that groundbreaking ball, Alva, part of the new money rich, was not welcomed into the established New York City social scene ruled by Mrs. Astor.

Besting Mrs. Astor’s 400, Alva invited 1,200 of New York’s finest to her ball. Mrs. Astor was conspicuously left off the guest list, until she came calling at Alva’s door, symbolically bowing to the new order as she sought an invitation for her and her daughter. Inside Alva’s home, guests were greeted in a hall built of stone quarried from Caen, France. The interiors were decorated from trips to Europe, with items from both antique shops and from “pillaging the ancient homes of impoverished nobility.” The Vanderbilts affectionately referred to their mansion as the Petit Chateau. Sadly, the mansion was demolished in 1926 after being sold to a real estate developer and in its stead rose 666 Fifth Avenue, an office tower.