Three Nordic Cities

A trip to Scandinavia in summer, with extra-long days showing off gorgeous scenery, is undoubtedly a treat. Go in winter, and you can do many of the same things, and enjoy what a Danish friend of mine calls ''the cozy season.''

Scandinavian cities in winter are a haven for lovers of the Great Indoors - restaurants, museums, cultural events, and other urban pleasures. Indoorsmen will enjoy the rugged mountains around Oslo, because they make them feel so glad to be under an eiderdown or in a sauna. And the early blackness of Stockholm sets off so nicely the blaze of the Museum of Modern Art's collection and the glow of festive dinners of herring and reindeer.

If you happen to like winter, of course, you can ski in Oslo, skate in Stockholm, and walk the docks in Copenhagen. But for indoorsmen, a northern winter sojourn is full of special comforts.

What could be more cozy than hot chocolate and pastry as the sun sets in Copenhagen at 4 o'clock? There are candles everywhere - in windows at Christmas and on every restaurant table. Sidewalk torches blaze at the doors of Stockholm restaurants and hotels. Museums, ballet, the symphony, and jazz clubs let you in on Danish, Norwegian, and Swedish life even if you don't know the languages.

Copenhagen is a calm, casual, comfortable place anytime. In winter, women wear pants and everyone is swathed in belted-down coats with shawl collars like bathrobes, but it's just raw and wet out, not icy. With its fanciful castles and low skyline, it's a city you want to cuddle up to. Wander down the Stroget, the pedestrian shopping street, to see how elegantly comfy life can get. There's the Royal Copenhagen china factory, which has a reasonably priced seconds store. Iliums Bolighus is just down the street, with its inspiringly crafted knitting needles and salt and pepper shakers, not to mention the crystal, ceramics, silverware, stainless steel, and clothing Denmark designs so well.

The Royal Theater, in Kongens Nytorv, the square at one end of the Stroget, is a wonderful place to see the world-class Royal Danish Ballet. The theater is a beautiful old building, rococo and dark crimson inside. Over the stage is the rather stern motto - ''Not just for pleasure'' - but that doesn't keep the audience from showing up in everything from blue jeans to furs.

The company is especially delightful at home. When they dance a Bournonville story ballet, it's family entertainment in the best sense of the word. The dancers have literally grown up in this building, studying both ballet and academics in the classrooms backstage from age 7 on. August Bournonville's distinctly Danish, well mannered, witty ballets are still danced here 100 years after his term as ballet master. Productions are lavish. The stage is thronged with wonderfully costumed dancers and ''bystanders'' from children up to age 90, with brilliant young soloists carrying the action. Arne Villumsen, one of the young stars, says that when he dances on this stage, he feels he is among his family.

A Bournonville ballet would be good to take children to, but go to a matinee, because evening performances are notorious for their long intermissions and don't get out until 11 o'clock.

To get a feeling for Copenhagen's shipping traditions (it was a trading village on an island that finally got enough protection from pirates 850 years ago to start thriving, and has ever since), take a blustery, ear-reddening saunter from Kongens Nytorv, down Nyhaven (pronounced ''New hown''), a street with a canal for a center lane. The docks begin at the end of the street, and in the middle of the street is a tiny restaurant in the schooner Isefjord. Step aboard and shinny down the hatch for a bowl of skipper lapsov, traditional sailor's stew made of potato and ham. First, sample several kinds of herring with rough brown bread, a delectable Scandinavian tradition.

The Little Mermaid (Copenhagen's famed sculpture) is within walking distance from the center of town if your ears are covered, or you can take bus 1, 6, or 9 . It's a nice trip in the afternoon, when the sea is dark blue, the clouds are pink and gray, and the sky is deepening in color. The mermaid is dark green and a ferryboat slips out behind her back for Poland, splashing the last of the light off its spanking white sides.

Just the setting for hot chocolate and pastry. Lumskebugten, nearby on the Esplanaden, is a lovely, 100-year-old, refurbished cafe. Painted creamy white inside, with old wainscoting and dark red chairs, it recalls the days when sailors mixed with high society here. The pastries are superb: apple pie topped with meringue, chocolate cake so moist it seems like a chocolate fog, and an incredible fruit salad with delicious tart red berries with an untranslatable Danish name. The hot chocolate is very good, served with whipped cream.

Oslo, an hour from Copenhagen by air, has a completely different character. December days are dim, with black pine trees, gray snow, and charcoal mountains. The cold is dry and bracing. But the big difference is the Norwegians, who love to rush outdoors. They ski after work on lighted municipal ski trails in the forest that surrounds the city, feeling, our guide explained, that it's better to join nature than to try to beat it. This attitude rubs off in small ways on the most intent indoorsman: Museum trips become outings, and snow is a delight. You'll find yourself doing much more after dark than at home. The city bustles then with the wholesome charm of an out-of-the-way ski town.

After a strapping Norwegian breakfast, take the tram up to the Holmenkollen ski jump. Outdoorsmen will find a place nearby to rent skis and take lessons or just glide into the forest. Indoorsmen can have a look at the view of the city sitting in a bowl of mountains at the edge of its fjord and then duck in the little door under the jump for the Ski Museum.

The museum really gives you an understanding of the culture that spawned the sport. There are ancient skis as well as handmade ones from the 19th century, when skiing was not a sport, but the only overland transportation in the remote Norwegian valleys, so isolated by the mountains that each one made skis differently. There are snowshoes for people and horses, and old photos of ski heroes line the walls. Snowshoe Thompson, who skied through the California gold rush, and Sondre Nordheim, inventor of the downhill ski, are two honored pioneers. The explorer Fridtjof Nansen donated his equipment, including a boat he made of the floor of a tent and some sticks to cross a fjord on his Greenland expedition. The skis on which Amundsen slid to the South Pole are here. They have replaceable bindings, because sled dogs liked to eat the leather. One picture strikes a more domestic note, with the royal family trekking on skis, then-four-year-old King Olav in the lead.

If this doesn't persuade you to hire a dog team and head out, return to Karl Johans Gate, chunky and comfortingly urban after the display of Antarctic tents.

Chocolate is useful for all sorts of expeditions. Buy a Bravo candy bar, which is described on the wrapper, aptly, as ''massiv,'' and take Universitets Gata off Karl Johans to a solid brick building with snarling griffons perched on its corners and languid, snow-covered stone nudes lolling on the lawn. This is the National Gallery.

The landscape paintings here show Norway at its most awesome. Frozen waterfalls mount up overwhelmingly among razor-sharp crags. Hillsides burst into flames. Mountains rise like ghosts out of dense mists. The paintings are utterly realistic, and they are gripping. They give you a feeling for Norwegians' love and respect for their incredible surroundings. The painters must have been as intrepid as the explorers, just to find some of these scenes.

The Edvard Munch gallery has some great pictures by the man who ventured inward. Munch said he painted ''The Scream'' after ''I felt a scream pass through nature.'' Looking at the landscapes of his countrymen, you know what he's talking about. His calmer portraits show, with the sensitivity of an Ingmar Bergman movie and graceful technique, faces with a lot going on behind them.

The general direction for this hearty people, though, is ''outward instead of inward,'' says Bard Kolltveit, curator of the Norwegian Maritime Museum. Their coastal waters form their only ice-free roadway, so it's no wonder Norwegians have been rushing out to sea since the Vikings. Bygdoy Peninsula, a 15-minute ride from city hall on the No. 30 bus, is an armchair-sailor's haven. Go when it's light, because the Maritime Museum has glass walls that jut out over Oslo Fjord, with a great view of the city and its mountains and ports. There are plenty of ship models, but Mr. Kolltveit is proudest of the ship interiors. You can sit on a 19th-century bunk in an old fo'c's'le or saunter through a mahogany-lined 1914 coastal steamer set up inside. ''We try to create an atmosphere of what a ship is as a means of transport, as a place to work, and a place to live.''

The Thor Heyerdahl museum is right next door, with the papyrus Ra II and the Kon Tiki. Farther along the peninsula is the Viking museum, a beautiful building constructed just to house three 1,000-year-old ships. They look all the more awesome under arched ceilings in their nave-like halls, arousing thoughts of that first voyage to America.

Stockholm, another hour's flight away, is as elegant as Oslo is wholesome. If they must go out, people here wear furs. Inside, they eat candlelight dinners. Gamla Stan, the old town, is a delightful walk on a wintry day. The tiny narrow streets, lined with shops and alleys, look all the more medieval in the dark, with torches made of cans of kerosene burning down the alleys.

The Modern Museum, once the preserve of avant-garde curator Pontus Hulten, who went on to direct the famous Pompidou Center in Paris and the yet-to-open Museum of Contemporary Art in Los Angeles, is still a Northern stronghold for the new. I went one afternoon in pitch darkness. It's on an island at the end of a peninsula (home of the National Gallery - also worth a visit for its international shows and national collection). But the view from a little wooden bridge of the lights of the old town and a schooner moored alongside is worth the walk.

The museum's photography collection is excellent, as are the modern paintings , including a huge Matisse cutout. My favorite, though, was a realistic landscape with a lake and a hill by a Swedish artist. Behind the hill a wolf, also realistic but tall as the hill, is chasing an equally oversize reindeer. Pleasantly mysterious and un-international.

The Kungstadgarden, a downtown park, has a skating rink, and nearby is the Opera, with restaurants attached. The Operakellaren, upstairs, has the biggest smorgasbord in Stockholm, and is very stylish. Downstairs is a crusty old rococo cafe with a greenhouse. There you can settle down for a light meal or some pastry, and watch the skaters.

The Grand Hotel lives up to its name. A huge expanse of ornate gray stone, it looks out on the water imperiously. The hotel once hired away the czar of Russia's cook, and it still serves a regal array of pickled herrings, smoked eel , and other native delicacies at its smorgasborg ($6.25 for lunch or dinner). On Sundays from 2 to 6, there is tea dancing in the Winter Garden, a fabulous mirrored, rococo hallway encrusted in 24-karat gold. Dancing (to Glen Millerish music) and cookies and a drink is about $8.25. If you are feeling more folksy, visit Skansen, a park full of traditional old-fashioned Swedish wood houses.

Everything mentioned in this article can be done in summer; Stockholm, a great beauty, is the one place I would rather see under more light. But a winter trip to any if the cities yields a more intimate view of the people and their culture - once you get inside and everyone takes the scarf off his nose - than you are likely to have when distracted by dazzling, 24-hour views of landscape in scandinavia's other season.

Practical details:

The schedule of the Royal Danes can change and the Royal Danes are very popular all through their season (September through May), so check ahead with your travel agent (if you go by SAS, the Scandinavian Airlines System, it will book tickets for you), and then check again when you get there. Next September, the theater closes for a two-year process of restoration; meanwhile performances will be in the theater at Tivoli.

SAS and Northwest Orient Airlines offer an off-season reduced fare of $395 until the end of April, and Copenhagen's hotel prices are generally lower in winter. Oslo and Stockholm are business capitals, so you get price breaks over the weekends, but they are less expensive in the summer.