Hike the Milford Track on the South Island, New Zealand
Here's a quick vocabulary lesson: New Zealand natives are often referred to as Kiwis, and Kiwis use the word tramp instead of hike. So if a Kiwi advises you to go tramping on the Milford Track, you should take it as sound advice. The Milford Track, a 33–mile trail in Fiordland National Park, stretches from Lake Te Anau to Milford Sound over one of the most spectacular swaths of land in the world. January means summertime in New Zealand, and with average daily highs of 68 degrees, it's the perfect time to hike the Milford Track. Sure, this is the most popular season to hike the trail—and for good reason, but the government regulates the number of people who can access it. You'll be sure to find your own little slice of Fiordland heaven (just plan well in advance to secure that much–coveted spot on the trail).

Snowshoe and Ski in the White Mountains, NH
Summer days on the Appalachian Trail in the White Mountains are a treat indeed. But winter brings to these mountains a peaceful beauty, along with plenty of wildlife and opportunities for adventure. The Appalachian Mountain Club maintains three huts during winter accessibly by either cross–country skis or snowshoes, depending on the route you choose. Once at the hut, with a cup of hot cocoa in hand, you can plot your ski or snowshoe trek for the next day. Keep your eyes open for moose, fox, spruce grouse, and many other creatures that roam the Whites.

Go Winter Kiting on Lake Simcoe, Ontario
Combine the airfoil and techniques used in kitesurfing with the footgear and hardware used for snowboarding or skiing, and, voila, you've got snowkiting. Once you master the technique, the pull of the kite can take you across snow on frozen lakes, rolling hills, and even up mountains. Head to Lake Simcoe, about 50 miles north of Ontario, for your first snowkiting experience. This is the mecca of the fledgling sport; and with 280 square miles of lake to glide on, you'll likely have enough space to avoid crashing into someone or something. Grant Fitz, an instructor and owner of Ontario–based Canadian Wind Rider (www.canadianwindrider.com; 416.497.9463), offers two– to three–hour courses.

Surf in Ecuador
You can surf year–round in equatorial Ecuador, but rumor has it that winter (specifically November through January) brings the best waves. Montañita is the surfing capital of Ecuador, and with so many spots to choose from, there's something for all levels. And if you have non–surfers in your crowd, they can always explore the mountains, jungles, and the mighty Amazon River.

Ice Bike in Vermont
It's counterintuitive at first. How can a bike, which relies partly on traction to propel itself, move forward on icy trails? But once you get used to riding a rig armed with a pair of studded tires, ice biking is supremely addictive. Riding a bike on ice requires more skill and energy than summer riding, but the peaceful, snowy–white scenery and creating the first tire tracks on virgin singletrack make the effort well worth it. Try the Rattlesnake Mountain trail in Vermont's Townshend State Park for excellent views and challenging terrain.

Construct an Igloo in Mount Baker National Forest, WA
Of course White Pass in the Mount Baker National Forest isn't the only place where you can build and camp in an igloo. But it's a great example of an area with the necessary igloo–building conditions—an elevation high enough to assure that the winter precipitation usually falls as snow rather than rain, and a plowed road to the trailhead. Plus on a clear day, you'll get great views of Goat Rocks Wilderness. Constructing an igloo is hard work, but you should really think of it as playing in the snow. And once it's built, you'll have a sturdy, quiet place to call your own for a night or more.

Paddle the Gulf Islands National Seashore, MS and FL
A drift of sandy islands south of Florida, Alabama, Mississippi, and Louisiana, the Gulf Islands extend for 150 miles parallel to the mainland, and are among the last undeveloped barrier islands on both the Atlantic and Gulf coasts. Wilderness camping is allowed year–round on East Ship Island and on the designated wilderness islands, Horn and Petit Bois. In winter, northerly winds make warm, wind–resistant clothing a necessity, but the summer crowds (and the brutal insects) are gone. Fourteen–mile–long Horn Island offers the best hiking through varied terrain that includes tidal marshes and pine forests, and it provides an important nesting area for ospreys, skimmers, terns, and snowy plovers, and a wintering area for rafts of other waterfowl.

Explore Patagonia's Tierra del Fuego
Tierra del Fuego, a scattering of islands separated from the rest of Patagonia by the Strait of Magellan, is the tip of South America's tail. To hardy trekkers and kayakers, Tierra del Fuego is known as a beautiful landscape of unexplored wilderness. But there's plenty of adventure on this isolated outpost for all appetites. Glimpse the largest flying birds in the world, the condor in the mountain regions and the albatross in the coastal areas. Head to Parque Nacmonal Tierra del Fuego, the southernmost national park in the world, for the capstone of your adventure.

Raft and Fish on the Skagit River, WA
January is one of the prime eagle–viewing months on the Skagit River in Washington. The best way to see these majestic birds is to take a guided rafting trip down the river (DIYers take note: unguided rafting is prohibited to protect the eagles' nesting area). You'll witness perhaps hundreds of bald eagles in their nests atop Douglas fir snags, and you may even see one or two tearing at a spent salmon carcass at the edge of the river. After your half–day of rafting, break out your rod and reel; this is the best time of year for salmon, trout, and steelhead on the Upper Skagit.

Bike the Turquoise Trail Byway, NM
Back roads almost always lead to great discoveries. And that certainly holds true for the Turquoise Trail National Scenic Byway, a 52–mile route that connects the high country of Santa Fe with the desert of Albuquerque. There will be plenty of people whizzing by you in cars, but the best way to see this breathtaking country is on two wheels. The byway is a passage back in time through old mining towns, plus thriving communities of artisans and craftsmen. If you're up for it, tack on the 12–mile trip to Sandia Crest—a worthy 3,700–foot climb from the Turquoise Trail at Sandia Park.