Tobago’s Pigeon Point Heritage Park. (M. Timothy O'Keefe/Alamy Stock Photo)

Turks and Caicos is not like the other Caribbean pairs: The country is a collective of 40 islands and cays categorized under “T” or “C.” However, several other inhabited islands are truer twosies, although they are hardly twins. Here is an overview of three sister isles and their distinct personalities.

Antigua and Barbuda: The country has only one international airport and one cruise port terminal, and both are on Antigua. Antigua is more developed than Barbuda: It has sprawling resorts and all-inclusives, such as Sandals, as well as shopping malls, high-end boutiques and a farmers market in the capital of St. John’s. The so-called Land of 365 Beaches boasts a beach for every day of the year, plus such historical sites as Nelson’s Dockyard National Park, which was named after 18th-century resident Admiral Horatio Nelson, and Betty’s Hope, a 17th-century sugar plantation that now houses an open-air museum.

Barbuda-bound travelers must connect through Antigua, where they can hail a ferry or puddle-jumper. The diminutive island — 62 square miles vs. Antigua’s 108 — has two hotels and several family-run guesthouses. Its handful of small shops are centered in Codrington, the island’s sole village. Barbuda is big on nature, with limestone caves, pink-sand beaches and birds galore, including the endemic Barbuda warbler (or Christmas bird) and the world’s largest colony of frigates. A sea taxi to the frigate sanctuary in Codrington Lagoon National Park required. Info: visitantiguabarbuda.com.

Trinidad and Tobago: Visitors must first fly or cruise into Trinidad, home of the country’s only international airport and port terminal. Ferries and planes offer connecting service to Tobago, 21 miles away. Trinidad is the size of Rhode Island and has the infrastructure — major hotel chains, multilane highways, bagel shop — to support the nearly half-million annual tourists. The capital of Port-of-Spain hosts the event of the year, Carnival, held the first two days before Ash Wednesday. Around the same time, leatherback turtles start to appear at Grande Riviere, the second-largest nesting ground in the world. Mount St. Benedict Abbey, the largest Benedictine monastery in the Caribbean, is the spiritual center of Pax Yogurt, which is made by the monks and sold at the abbey shop. The 12,000-acre Caroni Swamp contains a wildlife sanctuary frequented by scarlet ibis, the lipstick-pink national bird.

On the 115-square-mile Tobago, most of the lodgings and commercial services congregate on the southwest tip, leaving the rest of the island to run wild. The Main Ridge Forest Reserve (est. 1776) covers about two-thirds of the island and provides refuge for 16 lizard species; 210 bird species, including the endemic white-tailed sabrewing hummingbird; and the ocellated gecko, a lizard found only here. The island has a fort named King George (not to be confused with its neighbor’s Fort George) and a sweet indulgence made by Tobago Cocoa Estate. Traditions unique to Tobago still thrive: Keep your eyes and ears peeled for tambrin music and reel-and-jig dancing. Info: gotrinidadandtobago.com.

Nevis and St. Kitts: Both islands have international airports, although travelers to Nevis must connect through the Caribbean, whereas St. Kitts’s airport receives planes from East Coast gateways. St. Kitts, the larger of the two, features a strip of entertainment on Frigate Bay and keeps its lights on late with casinos and nightclubs. Military history buffs can poke around the Brimstone Hill Fortress National Park, a UNESCO World Heritage Site, and eco-adventurers can zip through the rain forest like Tarzan or summit Mount Liamuiga, a dormant volcano.

On the stoplight-free Nevis, vervet monkeys outnumber people. Goats, sheep and donkeys wander along roads and in the capital of Charlestown, a model of Georgian architecture. Several monuments and cultural centers pay tribute to such famous visitors and islanders as — no, not Britney and Justin — Lord Horatio Nelson and Alexander Hamilton, the treasurer-cum-Broadway star who was born here. Relaxation is a major sport, with volcanic hot springs and sugar plantations converted into high-end digs. At four miles long, Pinney’s Beach is the island’s longest — and softest — bed of sand. Info: nevisisland.com, stkittstourism.kn.

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