The Penthouse:  Terraced on every side, this elegant ten-room, full-floor home is ideal for grand scale entertaining.  The living room, library and master bedroom each have wood-burning fireplaces and tall French doors giving on to the sunny South terrace which overlooks the Park Avenue Armory.  A private elevator vestibule leads into the grand, central gallery.  The living room, 30 feet long with ceiling heights of almost 11 feet, flows graciously into the formal, corner dining room.  The apartment features a double-sized master bedroom, a large second bedroom with a dressing area and two smaller, contiguous rooms which could be a third bedroom.  There is also a staff room and wine room.  Originally fourteen rooms with three large bedrooms and four staff rooms, there remain many possibilities for configuring the private space. The Garden Apartment:  Perfectly complementing the penthouse as guest or staff quarters or an office suite for the residents above, every room of this charming, four-room apartment faces the beautifully planted, private garden.  It is comprised of a living room, two bedrooms, two full bathrooms and an eat-in kitchen. Millan House:  Built by John D. Rockefeller, Jr. in 1930, 115 East 67th Street and its twin, 116 East 68th Street, share a private formal garden and the unique vision on their architect, Andrew J. Thomas, who adorned the exteriors with multi-paned casements and fantastic carved creatures.  The buildings afford a discreet, prestigious address with incomparable services.  The cooperative allows pets.  Pied-a-terre purchase is permitted.