If you're like us, you'll plan an entire vacation around a great swimming pool. These days, there's one for every taste:

URBAN OASIS Berkeley Hotel London; 44-207/235-6000;; doubles from $322. Eight stories up, London's only alfresco rooftop pool (with a retractable roof that's slid open in summer) has splendid views over Knightsbridge and Hyde Park, a full-service spa, and a Christian Dior salon.

OLD-SCHOOL GLAMOUR Biltmore Hotel Coral Gables, Fla.; 800/727-1926 or 305/445-1926;; doubles from $259. Esther Williams performed aquatic shows here in the 1930's and Johnny Weissmuller was once the swimming instructor. At 22,000 square feet, it's still the largest pool in the continental U.S., and the Mediterranean Revival setting is as opulent as ever.

NEW-SCHOOL GLITZ Palms Casino Resort Las Vegas; 877/942-7777 or 702/942-7777;; doubles from $69. Open just nine months, this sexy resort has become the destination for Vegas hipsters and chic out-of-towners—not least for its 75,000-square-foot poolside lounge. After dark, the pool area becomes a sultry nightclub with dazzling lights, fog machines, live bands, and bikini-clad babes dancing on Plexiglas platforms over the water.

FOR OCEAN-LOVERS Rockhouse Hotel Negril, Jamaica; 876/957-4373;; doubles from $75. Surrounded on three sides by the Caribbean, the small saltwater pool is the ultimate spot to watch the sunset atop a floating mattress. Or dive off the adjacent rocks into a sheltered cove—to explore underwater caves and coral beds.

FOR FAMILIES St. Regis Monarch Beach Dana Point, Calif.; 800/722-1543 or 949/234-3200;; doubles from $245. This child-friendly (but refreshingly grown-up) resort opened last year, midway between Los Angeles and San Diego, and has a terrific four-foot-deep pool set aside for kids. What you may or may not choose to tell them: Disneyland is only 45 minutes away.