The Bar/Lounge at The St. Regis Istanbul
The St. Regis Istanbul's bar/lounge is acknowledged by those who travel for a living. Out of 4 publications tracked on TripExpert, 2 recommended the bar/lounge, like Fodor's and Star Service.
The St. Regis Istanbul 
Fodor's
Star Service
Fodor's "A rooftop bar, the first international branch of Wolfgang Puck’s Spago restaurant, and a lavish day spa facility are draws for nonguests as well"
Star Service "The 950 sq m Iridium Spa is like a day spa in the middle of the city, with three small relaxation pools, three Turkish baths, steam rooms, saunas, a tea bar, and seven treatment rooms offering a variety of traditional and modern therapies"
