ST. VINCENT & THE GRENADINES
Petit St. Vincent
Safe swimming, No crowds, Hotel, Cafés/bars, Natural shade

A two-mile-long idyllic beach almost completely encircles this islet near Union Island.

Wow Factor: PSV has sand so cushy that guests risk sinking up to their piña coladas.

Best Bed: The 113-acre island's only occupant is the Petit St. Vincent Resort, whose 22 cottages are just secluded enough—some beachside, some cliffside—to make this one of the most romantic spots on the planet, as well as one of the most private. No phone, TV, A/C, or room key (945-963-7401; psvresort.com; doubles, $605).

SPAIN
Playa de las Salinas, Ibiza
Safe swimming, Often crowded, Hotel, Cafés/bars, Natural shade

Every beach is a party beach on Ibiza, but this is the hippest.

Wow Factor: A mile-long stretch of sand backed by pines, it's where people who have the stamina to party all day after partying all night come to dance—and to pretend they don't notice just how little some people can get away with wearing to the beach. Visitors with an interest in either should come in the summer or not at all.

Best Bed: To party where you sleep, stay at urban funky El Hotel Pacha, connected with Club Pacha, an institution among Ibiza dance venues (34-971-315-963; elhotelpacha.com; doubles, $488).

TANZANIA
Bwejuu, Zanzibar
Safe swimming, Seldom crowded, Hotel, Cafés/bars, Natural shade

This 12-mile beach on the southeast coast is populated mostly by locals—fishermen wading to their boats, brightly dressed women husking coconuts or gathering seaweed, kids with dreams knocking around a deflated soccer ball.

Wow Factor: Zanzibar is one of the most exotic of African islands, and Bwejuu is its wide and blindingly white beach.

Best Bed: You'll find a few guesthouses, but for pampered luxury stay at The Palms, six large villas associated with the more modest Breezes Beach Club (225-777-437-007; palms-zanzibar.com; doubles, $1,235, all-inclusive).

THAILAND
Kamala Beach, Phuket
Safe swimming, Seldom crowded, Hotel, Cafés/bars

The western shores are thick with beaches, and many of those beaches are thick with commerce—food vendors, souvenir kiosks, girlie bars, and other distractions. It is possible to escape the commotion by retreating to an exclusive resort, but you risk missing the local color.