Cruising the far North Atlantic – Iceland and Greenland – is generally limited to the cramped confines of little expedition ships; but a couple of major lines do call there occasionally, allowing passengers to explore these remote regions in a high degree of comfort and luxury.

We sailed these northern waters on Radisson Seven Seas' Navigator, and learned a lot about the little-known lands that served as stepping-stones for the Vikings during their voyages to North America a thousand years ago. Because of their location, Iceland and Greenland can only be visited by sea in the summer months, particularly July and August.

Greenland-Ice floes

Our cruise was the return segment of two 10-day sailings that Navigator operated between New York and Reykjavik. We arrived in Iceland early enough to explore this rocky, volcanic island nation, a former territory of Denmark that achieved complete independence in 1944. Almost all its 290,000 inhabitants live along or near the coast, and 115,000 live in Reykjavik, the capital – a very European city with parks, public sculptures and sidewalk cafes in the heart of town, as well as an active harbor (more than half the country's economy is based on fishing). One caution: Iceland is expensive. A night in a three- or four-star hotel in the capital will cost $200-$300; a taxi ride into town from the airport at Keflavik can set you back more than $100 (although a reasonably priced bus service is available), and meals in good restaurants cost as much as in any major U.S. city.

Iceland is gaining a reputation for outdoor/adventure activities, and we set out from Reykjavik to try one: Snowmobiling on a glacier. A local tour company called The Activity Group (www.activity.is) arranges snowmobiling treks year-round, as well as dog sledding, all-terrain vehicle rides and river rafting. We climbed into one of the company's Super Jeeps – souped-up vehicles with huge tires, global positioning equipment and other extras designed to maneuver on the rugged, unpaved roads of Iceland's interior – and our driver headed out of Reykjavik.

We did a little sightseeing on our way to the giant Langjokull Glacier a couple of hours east of the capital. First we stopped at Thingvellier, a broad, scenic rift valley notable for two things: It was the site of the original Icelandic parliament, established more than 1,000 years ago; and running right through it is the Midatlantic Ridge, the place where the European and North American continental plates meet -- and separate. Long fractures run through the valley so visitors can see this geological phenomenon themselves. Then we visited a place called Geysir, where the main attractions are, of course, geysers (there's a gift shop, restaurant and hotel). At least one of them goes off every eight minutes or so, meaning that even the briefest visit will produce a sighting.

Hiking near Narsarsuaq, Greenland

We drove to the east edge of the Langjokull Glacier, stopping at the tour operator's base facility, where we were fitted with snowsuits, boots and helmets. Then we strode onto the ice – much of it a dirty black color, the remnants of volcanic activity – and boarded our snowmobiles. After brief instruction, we went zipping across the glacier's surface, stopping here and there for explanations of glacial phenomena (yes, it is melting) and viewing the occasional crevasse (they're clearly marked, and all these expeditions are guided). The air over the glacier was much cooler than the other places we stopped, but overall, summer temperatures in Iceland are moderate – mostly in the 60s or low 70s.

The next day we tried horseback riding. Icelandic horses are direct descendants of those the Vikings brought over, unmixed with other breeds for hundreds of years. They are small, sturdy horses with long manes and tails, and great for riding. We went to the Laxnes Horse Farm, about half an hour from Reykjavik (www.laxnes.is; they can pick you up and take you back to the city). The rides go into the nearby countryside, with a scenic backdrop of mountains and farms. Rides are accompanied by a Laxnes guide, who keeps the horses to a speed you're comfortable with. Besides the usual four "gaits" of horseback riding – walk, canter, trot, gallop – Icelandic horses have a fifth one that's unusually smooth.

Before heading to the ship, we made a side trip to the Blue Lagoon – a huge pool of hot water not far from the airport, and one of Iceland's most popular attractions for both tourists and locals. For a small fee, you can rent towels and swimwear and wade around in the soothing hot water, scooping up mud from the bottom and rubbing it on yourself—it's said to be great for the skin. The Blue Lagoon also has restaurants and a gift shop that sells its own brand of spa products.

Radisson Seven Seas Navigator used a day at sea to get from Reykjavik to southwest Greenland – which is actually farther south than Iceland. Greenland remains a territory of Denmark, and although it's much larger than Iceland, its population is much smaller—a mix of Inuits and Danes, mostly – since most of the country is covered by a massive ice cap. The Navigator had to skip its planned sail through Prince Kristian Fjord at the southern tip of Greenland – it was clogged with too much floating ice, even in August. The icebergs and floes can force changes in almost any cruise itinerary to Greenland, and the frequent fog can slow a ship down as well.

A geyser in Iceland

We first called at Qaqortoq, a town of 3,500 with brightly-colored little houses climbing up the mountainside. Tenders pull into the small harbor at the heart of Qaqortoq – most transportation in the region is by boat – and close by the pier is a tourist office/souvenir shop where you can pick up something to prove you actually visited Greenland. On a hill above the tourist office is a hotel. There are only a few shops in town, but its hills and the bright colors of its buildings make it visually interesting. Qaqortoq has some historic buildings and even a public fountain; close by is a small museum and a restaurant with outdoor tables.

We opted for a tour that involved hiking around the large lake on the edge of town. To our surprise, we ran across a group of children swimming in it, although to the touch the water hardly seemed warm enough – for non-Greenlanders, at least. The air temperature was fine, though – in the 50s – and the day was sunny. The hike was scenic; small yellow wildflowers lined the path between the lake and the mountains, and occasionally we'd be passed by local joggers.

Radisson Seven Seas offered other shore excursions at Qaqortoq, including a visit to the aforementioned restaurant, a walking tour of town, a visit to a sealskin tannery, a helicopter flight over the fjords, and a boat trip to visit the ruins of Hvalsey Church, a remnant of the Viking settlers who disappeared from Greenland 600 years ago.

Next day we sailed up Tunulliarfik Fjord, which was riddled with small icebergs, to the town of Narsarsuaq, population 160. Narsarsuaq got its start as an airfield built by the U.S. military just before World War II, and today it's the only international airport in this part of Greenland. The town has a hotel – Europeans often fly in here to go hiking – and a café called the Blue Ice that also serves as a tourist information center and outfitter. There's a museum in town, with historical items from Viking and Inuit settlers. But there's only one bus here, and it is used for everything from shore excursions to airport transportation – sometimes mixing the various groups together.

Qaqortoq, Greenland

We selected the ship's hiking excursion to the Flower Valley – a beautiful area outside Narsarsuaq that is basically a farm surrounded by rocky mountains, with a waterfall at one end and small river running through it. The four-mile hike, guided by a French student spending the summer there, was invigorating without being too taxing. We were passed along the way by a group of Danish hikers who were on their way up a steep hillside to visit Greenland's ice cap a couple of miles further on.

Other shore excursions available at Narsarsuaq included a boat trip up the fjord to see a glacier; small-plane flight-seeing to view the glaciers and fjords; a tour of the town and its museum; and a boat trip to a nearby town to visit the ruins of a farm established by Greenland's first Viking settler, Erik the Red, who came here from Iceland 1,000 years ago. Erik's son, Leif Ericsson, founded a temporary settlement in North America at L'Anse Aux Meadows, Newfoundland.

In fact, L'Anse Aux Meadows was a later stop on the itinerary – at least, it was scheduled to be. Unfortunately, a night of heavy fog along the coast of Labrador slowed the ship down so much that we had to skip that port. The Radisson Seven Seas Navigator visited Goose Bay, Labrador, and then proceeded on to destinations that are familiar on New England/Canada itineraries, including the historic fortress town of Louisbourg, Nova Scotia; Halifax; and Boston.

Glacier snowmobiling in Iceland

Radisson Seven Seas made the cruise a lot more meaningful for its passengers by serving up a steady series of expert lectures on the history of European exploration across the region, from Ireland's mythical St. Brendan the Navigator to the Vikings to John Cabot. Other lectures covered related areas, from the history of ship-building to the state of the Canadian fishing industry.

Needless to say, visiting these remote northern seas aboard the all-suite Radisson Seven Seas Navigator (www.rssc.com), with its spacious accommodations, gourmet dining, spa/fitness center, full-sized theater and evening entertainment, selection of lounges and bars, etc., provides vastly more comfort and luxury than you could ever find on a little expedition ship.

For 2005, the Radisson Seven Seas Navigator will operate a 10-night New York to Reykjavik cruise, via Greenland, departing June 15; the ship then spends 14 nights going from Reykjavik to Copenhagen. On July 20, it sails from Copenhagen on a 10-night cruise to Reykjavik via the Orkney Islands and other ports in Iceland. And on July 30, 2005, it sails from Reykjavik to New York by way of Greenland and eastern Canada.

Holland America's Maasdam will also call at Greenland and Iceland on both eastbound and westbound transatlantic segments when it makes a 35-day voyage from Boston to Europe and back again, sailing from Boston July 16, 2005.