Vermont's (if not the country's) most sensational retreat has added a 16th room—which is bigger news than it sounds when you consider that the majority of the "rooms" are lavishly decorated houses scattered about the 300-acre property. THE AVIARY is unlike any other building at Twin Farms: Instead of a woodsy cottage, it is a sexy, geometric affair with a wall of glass and an exposed chimney clad in copper. Inside is just a pinch of the Poconos, circa 1972—douglas fir beams, orange Ultrasuede upholstery, and a granite bathtub sunk decadently into the middle of the bedroom, next to the fireplace. Since it's impossible to use the tub without first standing stark naked in front of that glass wall, you may at first find The Aviary awfully racy. Then you realize: Around this house, at the end of a road on the side of a mountain, there's not a soul to see you. Rate, $1,850. In Barnard, Vermont; 800-234-9999; www.twinfarms.com.