Hidden behind a dozen houses on the Upper East Side exists one of New York's most exclusive leafy enclaves, Jones Wood Garden, a private sanctuary accessible only through the townhouses that surround itand one of those houses, 160 East 66th Street, is now on the market for $11.9 million. The buyers will hold one of just 12 keys to the garden (you think Gramercy Park is exclusive? There are a whopping 383 keys to it, and it's on Google Maps). The house, recently renovated by Jean-Luc Briguet Architecture, is also pretty nice. The brokerbabble says it is "pin-drop quiet," and it features a wood-paneled library, four bedrooms, several wood-burning fireplaces, a rooftop terrace, and a "dramatic Regency-style 13' tall bowed" overlooking the garden from the living room.