Lee Radziwill's Apartment on Park Ave. (NYC) as of 2011
Cartier Boutique on 5th Avenue, NY
Grand Central has an AMAZING whispering gallery.You walk to the corridor outside the famous Oyster Bar & Restaurant. You'll see four low arches, built by a father and son back in 1913...If you and a friend stand at diagonal corners of the arches (so you're the farthest apart you can be), and whisper softly, you'll be able to HEAR each other--as clearly as if you were whispering into each other's ears!
Look Up! The Coolest Rooftop Gardens In NYC...slide show