Carrere & Hastings

35 East 68th Street, located between Park and Madison Avenues on the Upper East Side, is one of those buildings that is not to be messed with. It's a 13,000-square-foot Beaux Arts mansion designed as a private residence for Harvard-trained physician Dr. Edward Kellogg and grain fortune heiress Mary Dows by Carrere & Hastings–the same architecture firm behind the New York Public Library. Since the now-landmarked building was completed in 1901, it has maintained its elegant, carved limestone facade. The interior, however, is a different story. Somewhere along the line the mansion was converted into a co-op apartment building, split into eight units. Seven of the eight co-ops were on the market this February for $34 million, but it looks like a sale never happened. Now this three-bedroom duplex is up for sale on its own.
See the interior