Wow Factor: Animals far outnumber people (cimuseum.org lists fauna), with only 300 visitors allowed per day—about 18 per mile of beach.

Best Bed: Actually, the only beds. They're in the Greyfield Inn, an old Carnegie manor where guests gather for superb dinners (904-261-6408; greyfieldinn.com; doubles, $350–$575).

BRAZIL
Baía do Sancho, Fernando de Noronha
Safe swimming, No crowds

Turquoise seas rolling into a secret cove of golden sand make this perhaps the most visually stunning beach in South America.

Wow Factor: The reward is a heaven of sand with no hotels, bars, or peddlers.

Best Bed: The newest and most luxe stay on the island is Pousada Maravilha (55-81-3619-0028; pousadamaravilha.com.br; doubles, $615–$740).

Fair Warning: The beach is accessible only by boat or an intimidating passage down a nearly vertical rock face.

Hint: Fly from Recife or Natal to Fernando de Noronha.

ANDAMAN ISLANDS
Beach No. 7, Havelock Island
Safe swimming, No crowds, Hotel, Cafés/bars, Natural shade

This nearly untouched, mile-plus sugar-white crescent, backed by the kind of hardwood forest you pray that makers of lawn furniture never hear about, is known simply by a number—proof that marketing people haven't discovered the Andamans yet.

Wow Factor: Divers—at least the romantically inclined ones—say the water lapping it has all the greens and blues of a December birthstone.

Best Bed: Barefoot at Havelock's cottages and villas face the beach (91-3192-282151; doubles, $75–$105). Go to barefootindia.com for island and resort details.

Fair Warning: Havelock is two hours by boat from the islands' capital, Port Blair.

ANTIGUA AND BARBUDA
Palmetto Point Beach, Barbuda
Safe swimming, No crowds, Hotel

The breathtaking seven-mile southwestern beach is totally unspoiled, possibly because this is one of the less charming Caribbean islands.

Wow Factor: Barbuda's abundant shell-pink sands are one of its main exports.

Best Bed: Coco Point Lodge lures WASPy families, some of whom have been returning for generations (268-462-3816; cocopoint.com; doubles, $810–$1,485, all-inclusive; open Nov.–April), while the new kid on the beach is the sleek, white, sexy Beach House, which has its own boat and lobster cookouts on the sand (631-537-1352; caribbeanclubs.net; doubles, $750–$975).