Hawaii's newest major resort features the peerless King's Pond, a 3/4-acre saltwater lagoon housed in a black, lava-rock-walled pit. Set up like a conventional swimming pool, surrounded by beach chairs and a hot tub, with waitress service and towels, the King's Pond is distinctive for its denizens: three spotted eagle rays that soar through the water on their broad wings, and more than 3,500 colorful fish. Guests can feed the rays daily under the guidance of the resort's beach boys. The pool is linked to an underground ocean channel, which raises and drops the water level with the tides, and is best enjoyed using the fins, masks, and snorkels that the hotel provides free to guests.

The resort also offers three other, more conventional pools, including an infinity pool overlooking the Pacific. Each has a distinctive ambience, ranging from private to lively. $475-$950; (888) 340-5662; www.fourseasons.com/hualalai

Hyatt Regency Cerromar Beach Resort & Casino, Dorado, Puerto Rico
A recent, $60 million top-to-bottom renovation at this Caribbean classic did not overlook the pools. Cerromar claims the world's longest river pool: a skinny, meandering channel that guests can swim or float down. The pool, 526 feet longer than the Empire State Building laid on its side, covers nearly a third of a mile as it passes waterfalls and several hot tubs before emptying into a large free-form pool. Altogether, the complex boasts four water slides, 14 waterfalls, and a swim-up bar. $375-$535; (800) 554-9288; www.hyatt.com

Loews Portofino Bay Hotel at Universal Orlando, Florida