Though the main, Fountain Pool is lovely, it pretty much becomes an after-thought once you a climb a series of steps to the Serenity Pool. Adults-only, infinity, 2,650 square feet, Pacific views—it's got all the right adjectives. For the 60 guests allowed up there (go early to get a seat), attendants serve fresh fruit and muffins, and even offer massages. In the pool, there's a tasteful swim-up bar, and underwater sound system.
Rooms from $485, Four Seasons Resort Maui at Wailea.