Robert R.5/25/10...have a Hennessy Smash (or any other drink) and go undercover in a alcove! Check out the link for image...
201 Park Ave South
New York, NY 10003
Tucked beneath the Union Square W Hotel is yet another Rande Gerber hotspot. Start off upstairs in the hotel bar, Olives, for an after work cocktail and then head down the candlelit staircase from 17th Street to the low-lit dark and edgy Underbar. Red velvet padded walls, plush couches strewn with pillows, and intimate private niches draped with curtains make up the provocative atmosphere.
Brandt B.12/6/09hidden side lounges!
Ajay C.1/11/12yes it is underground but a modern feel, small place but do pop in!
EchoDA 12/29/11Yes it is under ground!, very mellow and quiet, its part of the W-hotel..although DJ's are around, so it can get busy in there, if you are near union square then drop in a take a peak
Glenn D.7/1/12Try the fried clam strips - Anything fried is good especially local clams (via @Foodspotting)