The Caribbean is notorious for "island time" -- spend two weeks here and you'll agree the rest of the world is just too fast -- but there's one country that's punching in on its own clock. You may not be familiar with St. Kitts and its sister island Nevis, but soon enough, I guarantee you'll be hearing all about these two unique sanctuaries, which are taking off in two very different directions.

The Caribbean's underdogs are proudly old-school, with little infrastructure and seemingly more animals than humans, including free-roaming wild goat, sheep, and cow. (They're also the only islands brimming with green vervet monkeys.) St. Kitts and Nevis are both shaking things up, their independent governments active with new initiatives. While St. Kitts has plans to reinvent the island as a residential playground for the rich and famous (or just rich), Nevis is taking its roots even more earthy: The island will soon run entirely on geothermal and renewable energy, making it the first in the world.

I have to admit, I always dismissed St. Kitts as that island with just a Marriott. And in all fairness, St. Kitts never fully went out of its way to lure visitors, surviving sufficiently on its sugar industry. The first English settlement in the Caribbean was perhaps the last island to capitalize on tourism, fueled only recently thanks to the worldwide recession -- the government started building, and fast. The island is experiencing one of the most accelerated real estate booms in Caribbean history. Not only do they want you to visit, they want you to live here. Condo residences like Scotch Bonnet, Ocean's Edge, and Silver Reel are popping all over unused land (St. Kitts is widely underdeveloped), some still under construction but all wooing visitors with the opportunity to have a second home—and dual citizenship. Those who buy investment at a minimum rate are able to apply for citizenship -- UK, Asia, Canada -- with perks like off-shore banking and visa-free travel.

Perhaps the biggest real estate development in this trend is Christophe Harbour. In its third year of development, Christophe Harbour will be a self-contained, lifestyle driven haven on the southeastern peninsula of the island. When it's completely finished—fingers crossed for the next five year mark—it will be the largest continuous property in the Caribbean at a whopping 2,500 acres. Not only will it offer 1,400 residence units (it's designed for 2,000) it will also include a boutique hotel, a luxury hotel operated by Mandarin Oriental Group, a club house with restaurant and Infinity-edge pool, an 18-hole, Fazio-designed golf course, six beaches and a marina with 300 slips, including 60 for mega-yachts. The project is conceptualized by the family-run Kiawah Island property in South Carolina, and if history and reputation proves, Christophe Harbour is going to be exceptional.

The first indication it will bring swank and style is its Turtle Beach Bungalows. These are four, 600-square foot cottages completely isolated on Turtle Beach, built specifically for potential real estate buyers and never meant to be booked by vacationers. But some journalist at some glossy discovered them, praised them and now they're up for reservations (actually, only by contacting the concierge, as there's no online booking tool). The pavilions are made of hand-hewn local wood with marble slab showers, three plantation-style shutter walls and unbroken views of the Caribbean and sister island Nevis. Each is also equipped with a tiered patio as large as the bungalow itself with plunge pool, a gazebo, and direct access to the beach. There's an all-inclusive mini-bar (including booze!), outdoor rain shower and free WiFi to boot.

The other property that's currently open is the year-old Beach House, a seaside restaurant next door to the bungalows, touted as the best restaurant on the island by locals and visitors alike. From an environmental perspective, Christophe is thankfully aware. They kept most of the land in its natural state (including peaks and ridges) and plan on keeping light pollution reduced so the unobstructed night sky is still magnetic. Islanders are considerably optimistic about Christophe Harbour, as it will bring hundreds of new jobs and improve the education system by employing new fields (real estate, construction) to expand the labor pool.

While Christophe Harbour may be the island's next big thing, St. Kitts is still a destination worthy of a quick jaunt. It's home to one of few World Heritage Sites in the Caribbean, Brimstone Hill, an 18th-century fortress on a hill that captures some of the island's best views. Thanks to the three medical schools and reputable veterinarian school, the island is sprawling with international graduate students who keep it young and create a wild nightlife even out of high season, mostly at beachside Dock Bar and Mr. X Shiggidy Shack at Frigate Bay. The rain forest is unique: it's actually expanding rather than shrinking, and hikers agree it's one of the Caribbean's best. The island also offers some charming surprises, like Ottley's Plantation Inn, a former sugar estate, and Le Belle Vie, a fine-dining French restaurant. In terms of infrastructure, the island is well equipped and well-prepared to expand their current 30,000 population, hoping to be more progressive and become the little island that, not only could, but did.

Nevis, on the other hand, is as retro as you can get. There are no street lamps, no fast-food or retail chains, no casinos, and long-abided, hundred-year-old laws are still in practice (cursing and nudity is illegal). To further preserve the island's sanctuary and eco-practice, fossil fuel electricity will soon be extinct. Last August, the island unveiled a wind farm comprising eight turbines, each with the potential to produce 275,000 kilowatts (for a total of 2.2 megawatts) of power. When the wind is blowing perfectly, on a good day, the mills go at max, producing 20 percent of the island's power.

But that's apparently not good enough. There's been major movement to make the entire island run completely on geothermal and renewable energy. While this has been a pipe dream for other islands like Guadalupe and Dominica, nothing has ever come to fruition. Nevis has drawn test wells down to the earth's core, which produce steam expansions that generate the electricity, so the heat source is the Earth rather than coal. The entire plant should generate 10 megawatts of electricity. Three production wells of 7,000 feet deep and 2 feet wide will be drilled to kick off the project, and they believe all will be ready to go by first quarter 2012. This will make the island completely "green" and fossil fuels will become entirely obsolete, which will only make the island even more authentic. But, even now, Nevis is still pretty old-school, perhaps the most in the Caribbean.

Four of the island's best hotels are former 18th-century plantation homes, all well preserved. One of the leading resorts is Nisbet Plantation, the only one on a strip of beach. The 32 cottages—shutter windows, ceiling fans, no TVs—are spread on sprawling green lawn toothpicked by a grid of swaying palm trees. It's here where a company in China chose to test out electric scooters, planned to roll out (if successful) throughout the rest of the Caribbean and reflecting Nesbit's dedication to eco-sustainability. Over at Golden Rock, famous American painter Brice Marden became a partner three years ago. I met him for their signature lobster sandwich as monkeys freely meandered the premises. Brice and his wife, another artist, gave the plantation a facelift, painting shutters a bold red to enhance the architecture and also unveiling a new, outdoor restaurant with hand-made Nevisian stone flooring, waterfalls and ponds full of tilapia fish . At first glance, one would think, "Hey, this looks very Aman," which would turn out to be an accurate observation. The deck was executed by Brice's friend Eric Tuttle, the designer responsible for several Aman resorts.

Speaking of Aman, the luxury brand plans on building a 40-room villa on the South end of the island. On a small, 26-square-mile island, this is the buzz on the dirt streets. While they begin the initial groundwork, return visitors will still have Four Seasons Nevis, which recently reopened after being closed for several years due to hurricane damages, perhaps a blessing in disguise—the resort needed renovations, despite it being a 5-Diamond property since it opened twenty years ago. With the re-opening, they bagged mandatory fine-dining resort attire in Coral Grill, added infinity edges to two of their three pools, and built four, 200-square-foot beach cabanas for a heightened, personalized experience. Four Seasons Nevis offers some activities you can't do anywhere else on the island, including Dive N Dine, where you explore the depths of the sea with the executive chef and pick out your own seafood; Nevisian massage that utilizes the local volcanic sand (concocted with a "secret recipe") for exfoliation; play tennis with a pro in one of their many courts; and witness a memorable sunset no other property can deliver (facing west, Four Seasons Nevis has the best, sprawling, unobstructed views). Don't ever feel like leaving? The resort plans to expand their portfolio of 68, million-dollar villas which you can rent or buy.