The Pool at Fairmont San Francisco

"A local institution that's been around since I was a kid is the hotel's Tonga Room, a Disneyland-like tropical bar and restaurant where happy hour hops with bands playing on a floating island in a pool, and there's a "rain storm" every 30 minutes"

"YOU SHOULD KNOW While the pool of the Tonga Room looks inviting, do not attempt to dive in--the water is not filtered"