39 Degrees at the Sky Hotel
A hipper-than-thou vibe permeates this chic hotel bar that spills out to a heated pool, waterfall, and pair of fire pits. After dark, Prada-clad scenesters fill the couches and leather chairs that flank candlelit tables; during the day, the focus is less on doing laps than it is on lapping up martinis. But if you can fight your way past the attitude, you'll find a gorgeous view of Ajax, excellent drinks, and a good lounge menu.
Tip: Bring your swimsuit. You don't have to be a guest at the hotel to enjoy a dip in the pool, but you do have to buy a beverage.