What kind of place is it? Mavi Köse falls somewhere between bar, tavern, club, and hookah lounge — one shape the nightlife category takes in Gölcük. Who's the crowd? It ranges from a young club scene to an older tavern crowd, and where Mavi Köse lands on that range is part of what you're there to find out. Do I need a reservation? Smart on weekends, usually unnecessary on weekdays — a special event night is the exception that can fill up fast.