Guide to Christmas in Oslo – Top 5 Things to Do

Planning on spending the holidays in Oslo? Check out our guide for best Christmas activities and what you need to know.

Are you planning or considering spending the holidays in Oslo? It’s a great time to visit the Norwegian capital, and experience snow, the cold dark evenings that make you crave for a cup of hot chocolate, and enjoy the seasonal attractions.

First a few practical things you might want to be aware of:

  • In Norway, Christmas celebration happens on Christmas Eve (yes, we’re that impatient). 
  • If you are one of those people that leave Christmas shopping literally to the last minute, do keep in mind that most shops are closed on the 24th, and remain closed on the 25th and 26th (your wallet will be grateful)
  • Only a few restaurants are open on Christmas Eve, and you are most likely going to find an open restaurant in a hotel
  • Public transport operates with limited service, however taxis operate throughout the holidays. For public transport, see Ruter’s Christmas service guide.
  • Many restaurants remain closed between Christmas and the beginning of January
  • Vinmonopolet, the only alcoholic beverage retailer in Norway, is open on the 22nd December and closed 23-26 December.

Here is our list of top 5 activities for Christmas time in Oslo

  1. Winter Wonderland in Oslo

    The Winter Wonderland Christmas Market in Spikersuppa, by Karl Johans gate.
    Put your balance to the test in the ice skating rink, enjoy a gorgeous view over the city from the top of the Ferris wheel, taste your way through the numerous stalls with all types of Christmas treats, warm up with a cup of hot mulled wine (which, ironically enough, is not part of the Norwegian Christmas tradition) and snap a few selfies in the season’s most Instagram friendly spot, the light tunnel, which you’ll find on the Stortingsgata side of the market. Free entry. Open until 30 December. Hours vary by day, check the day’s hours here.

  2. Christmas market at Bærums Verk

    Some 45-minute bus ride or a half an hour car ride from central Oslo takes you to Bærums Verk, a small village nestled in a valley by the river Lomma. It used to be the home of a factory producing metal castings, and is now a popular residential area with some 40+ shops, art galleries, a sculpture park, restaurants and cafes in the historical surroundings. There is a Christmas market until 23rd December and various Christmas activities suited for grown ups and especially families, such as a choir, horse riding and so on. Take the bus number 150 from Oslo, or the E18 towards Sandvika. Bærums Verk website (available only in Norwegian).
    Baerums Verk

  3. Christmas Cruise by the Oslo Fjord to Drøbak

    Another great way to get into Christmas spirit is a fjord cruise to Drøbak, a small, cosy costal town where you can visit Santa’s house. Many of the town’s old wooden houses date back as far as the 18th century, when the town established as a local hub for shipping and fishing. While Drøbak is a great destination for a summertime day trip, a cruise along the Oslo fjord is guaranteed to get you in festive spirit in no time. The cruise and a couple of hours in Drøbak takes approximately 5 hours. Cruises depart from Langaika (across the Opera house) until 30.12. Advance booking is recommended. Read more.

    Vision of the Fjords
    Vision of the Fjords, the hybrid ferry, pictured by the Akershus fortress in Oslo.

    Engebret Cafe
    Engebret Cafe.
  4. Traditional Norwegian Christmas platter (juletallerken)

    In case you’re wondering what Norwegians eat for Christmas, there really is no national consensus. Lamb or mutton is popular In the West and North of Norway (dish called pinnekjøtt), while in the East you’ll likely see ribs. But what’s even more popular before Christmas is a traditional Christmas platter “juletallerken”, which is essentially a little bit of everything, typically sausages, ribs, braised red cabbage, potatoes, meat cakes and gravy. You’ll find juletallerken in many traditional restaurants, but Bristol Grill  and Engebret Cafe are among the local’s favourites. Wondering what to drink with your Christmas platter? Try aquavit (akevitt), a Scandinavian distilled spirit for a classic pairing with your meal.

    Julelunsj Engebret
    Christmas platter at Engebret Café. Photo: DN.
  5. Christmas Concerts in Oslo

    What would Christmas be without appropriate music? It’s busy days for music fans as there are several concerts around the city each day. Oslo Philharmonic Christmas concerts are among the most popular (find available tickets here), but there are options for each taste. Check out upcoming concerts here.

3 Best Views in Oslo

Unlike many other European capitals, Oslo is far from flat. This means that there are also plenty of great viewpoints that offer breathtaking views. Here are our top pics:

Frognerseteren restaurant
The Frognerseteren restaurant. Photo:
  1. Frognerseteren

    Situated at the top of the same hills as the Holmenkollen ski jumping tower, Frognerseteren is also the last stop of the tube line that carries the same name. It’s fair to say that Frognerseteren is the vantage point for many visitors, and it’s not just that: there is a traditional restaurant, several hiking and skiing tracks, a 2 km (1,24 miles) toboggan run and much more, depending on the season. You’ll get there by car (parking area just outside the Frognerseteren restaurant) or the tube (the Frognerseteren line). We recommend taking the tube and admiring the views of the city on the way.

    Frognerseteren restaurant: Holmenkollveien 200.

    Night view from Ekeberg. Photo: VisitOslo/NLE Film
  2. Ekeberg

    Ekeberg refers to a residential area, a sculpture park, a recently renovated restaurant in funkis style and a viewpoint across from Holmenkollen and Frognerseteren. Ekeberg is closer to the city (some 10 minutes on the tram #18 or #19, or 5 mins by car) and offers a great view of the most urban Oslo, as well as probably the best view of the entire Holmenkollen area. The sunsets from Ekeberg are worth the trip up, but you will also want to experience the top restaurant and the sculpture park just behind the restaurant.

    A fun fact: The restaurant and the sculpture park are initiatives by the art-loving brewery heir Christian Ringnes  who believes that art belongs to everyone, and has donated art to public places on several occasions. He was also the person who took initiative to restore the worn-down funkis style building that now hosts a top restaurant.

    Ekeberg restaurant: Kongsveien 15.

    View from Grefsenkollen. Photo:
  3. Grefsenkollen

    The viewpoint that really deserves more attention is Grefsenkollen. It’s some 20-30 minutes drive from the city center, but the view is definitely worth the visit. If you are depending on public transport, you’ll need to change busses on the way (our recommendation: check instructions with Google maps or the Ruter app), but you should reach your destination in no more than 1,5 hours. Aside from a viewpoint, the Grefsenkollen restaurant is definitely worth the trip up, but we strongly recommend you check the opening hours before you leave feeling hungry, as the restaurant is not open all evenings.

    Grefsenkollen restaurant: Grefsenkollveien 100.


    View of Frognerkilen from a ship. Holmenkollen to the right, Bygdøy to the left. Photo:

    Bonus view: Oslofjord

    Many visitors arrive Oslo on a cruise ship, and therefore get to enjoy an unusual view of Oslo: from the fjord. This will allow you to see large areas of Oslo, including Holmenkollen, the city center, Bygdøy with its many museums and the Aker Brygge and Akershus Fortress area.

    This view is reserved for the ones arrive on a ship because most of central Oslo, including the areas just mentioned, is no-fly zone for drones, so you won’t be able to capture the same views with a drone camera. Check out our Instagram post for more footage of the 4th perspective to Oslo.

Oslo shopping guide: Top 10 Norwegian and Scandinavian brands

We put together a list of top Norwegian and Scandinavian brands that can be hard to find elsewhere.


The international luxury shopping scene in Oslo has definitely evolved during the last few years, but aside from the well known designer houses there are some local – or Nordic – brands that you might want to know about. Here is a list of Norwegian and other Nordic brands that might be hard to find elsewhere.

1. Aphru.
One of my personal favourites, Aphru is what you get when you couple Norwegian comfort with Italian design and quality. Timeless pieces for women in high quality materials, designed in Norway and made in Milan, Italy. I adore the simple, timeless designs and the trademark Italian finishing. This is a brand you will not find anywhere else, but will fall in love with if you are into minimalistic design and functional materials. Why not grab one of their dresses or tops for your flight home. The store is located in shopping center Paleet, Karl Johans gate 37-43.

by Timo store at Paleet. Photo:

2. By Timo.
The feminine, vintage-inspired dresses from by TiMo have taken the fashionistas around Europe and beyond (their designs are available at Barneys in New York) by storm. The brand was founded by Ms Tine Mollatt, who is still the heart and soul – creative director – for the company. A visit to their store in Oslo (in the same shopping center as Aphru) is like a little escape: the boutique is decorated with plants and vintage items for a unique experience. Paleet, Karl Johans gate 37-43.

3. Swims
As counterintuitive as it sounds, it’s actually quite logical that the people that wanted to make galoshes (those rubber things you pull on your shoes on rainy days) orange come from Norway: it’s a country where you wear galoshes a lot. Any time of the year. However, it was while he was studying in New York that founder Johan Ringdal came up with the idea to start Swims. Swims is a living proof that weatherproof can be stylish, and with their galoshes, shoes, coats and other accessories for men and women, rain won’t ruin your day or style. The Swims brand store is in Prinsensgate 25.

Swims rubber boots. Photo:

4. Illums Bolighus
This Danish design department store Illums Bolighus is not a Norwegian brand, but carries several Norwegian lifestyle, fashion and home brands among a large number of other Nordic and international designers (for example Georg Jensen, Decadent, Iittala, Alessi). From Norwegian brands, you’ll find here for example the minimalistic ceramics from Meant, watches from the Oslo-based watchmaker Harper & Brooks and beautiful, stone-like soaps from Stone Soap Spa. Being Danish, Illums Bolighus carries a large number of Danish kitchenware, home textile, fashion and accessory brands. Definitely worth a visit! Address: Haakon VIIs gate 10.

5. Filippa K
Known for its minimalistic designs and high quality, Filippa K offers both trendy and timeless fashion for men and women. Øvre Slottsgate 11.

6. Marimekko
The Finnish design icon known for its colourful print textiles and stripe t-shirts also has tableware and accessories, such as canvas bags. Marimekko truly has redefined “timeless” when it comes to design: for example their classical stipe shirt design is over 50 years old, yet never gets old or outdated. Øvre Slottsgate 17.

Bergans backpacks. Photo:

Outdoor gear
If there is one thing the Scandinavians do better than anyone, it’s definitely outdoor gear. And it’s not a surprise, as nature is an integral part of the Nordic lifestyle – whether it rains or shines.

7. Norrøna
One of the top brands is Norwegian Norrøna. High quality, functionality and cool design come together in their collections that are designed by activity: skiing, biking, hiking, surfing and so on. They are also committed to sustainability and offer services for fixing their products, so you don’t have to buy a new one. The Norrøna flagship store is located in Akersgata 30.

8. Bergans
Another Norwegian outdoor brand is Bergans, which manufactures everything from clothing to tents, backpacks and hiking equipment. Bergans flagship store: Kronprinsesse Märthas plass 1.

9. Haglöfs
Haglöfs is a Swedish outdoor brand that makes clothing, backpacks, dry bags and also has footwear. Grensen 8.

10. Fjällreven
The Kånken backpack was designed in 1978, and is still the best selling product from the Swedish outdoor brand Fjällreven. Karl Johans Gate 19.

5+1 reasons why Oslo should be on your bucket list

What makes Oslo so special from Stockholm, Copenhagen or Helsinki?

The Oslo Opera House. Photo: VisitOSLO/NLE Film

Oslo is a city that many tourists merely see as a stop on their way to the fjords on the west coast, the Midnight Sun in the North or the breathtaking nature on the Lofoten islands.

Then there is also competition from other Nordic capitals: Stockholm being the biggest and perhaps the best known, Copenhagen known for its Little Mermaid Statue, and Helsinki, which is particularly known among design and architecture lovers (disclaimer: my previous home town for almost 10 years). But having visited all those cities several times, I can reveal Oslo has something unique: it really has it all.

Here are our top reasons for visiting Oslo:

  1. You only need a day or two

    Got only a day? Or maybe 2? No problem. If you’ve ever been to London, Paris or New York for the first time (let’s not even begin with cities such as Shanghai or Delhi), you know how meticulous planning it takes to ensure you get to cross just a thing or two off your list because of long distances, complex public transport, long queues to sights or simply just because of the overwhelming amount of things to see or do. Oslo is super compact, which means that those with limited time will be able to get a taste of everything: the nature, culture, shopping, sightseeing and literally tasting Norway – even if you’ve only got a day.

  2. Architecture, design and art in Oslo

    The new Oslo Opera House was opened in April 2008 and has since then become, to many, the symbol for the entire city. Designed by the Oslo-based architecture firm Snøhetta (they are located just some 10-15 minutes walk from the Opera House, behind the Akershus Fortress), the Opera House is not only a stunning example of contemporary public architecture, but also houses a cafe and a restaurant that are both open to public.

    Another Great example of contemporary architecture is the Astrup Fearnley Museum of modern art. Designed by the Italian architect Renzo Piano, the museum is located in Tjuvholmen, an area entirely built after 2010, offering several other pieces of interesting architecture, such as the hotel Thief.

    If you’re into funkis architecture, you will get a 3-for-1 deal by taking a trip up to Ekebergrestauranten: the building is a fantastic piece of recently fully refurbished funkis architecture and offers one of the best views in Oslo, as well as local flavours on the menu.

    On the other side of the city, Vigelandsparken is a short tram ride from the city center and the world’s largest sculpture park with works from only one sculptor, Gustav Vigeland.

    Akerselva river. Photo: VisitOSLO/Didrick Stenersen.
  3. Nature

    While Stockholm consists of a large number of islands, Helsinki covers a wide area and Copenhagen is where the Nordics meet Continental Europe, Oslo is densely populated and surrounded by hills that offer unique spots for sightseeing. It’s also a capital where you can literally “ski in and ski out of the tube”.

    The Oslo people love outdoor life, and the public transport system extends to locations that would normally not be within reach by a bus or the tube. In Oslo, a nature experience really doesn’t require a daytrip out of the city.

    Frognerseteren and Holmenkollen are popular tourist attractions, however if you feel like a walk in the woods, you can still take the same tube up to Frognerseteren and follow one of the marked trails or ski tracks to enjoy the forests that surround Oslo (“marka”). Another option is to take the tube up to to Sognsvann, which is a lake and a very popular place for family outings, running, hiking or skiing in the winter. You need a total of 2-3 hours for a the tube rides and quick lunch at Frognerseteren, or a walk around Sognsvann. Just remember Sognsvann doesn’t have a restaurant.

    A walk along the river Akerselva is always a good idea – just remember that the walk is heavier if you start from the city center. Summer: If you enjoy long walks, head all the way up to Brekkedammen with a towel and packed lunch for a refreshing swim in the lake or just to enjoy the lovely lake view.

    Similarly, the many islands just outside the Oslo city are great for a picnic and you get there conveniently on boats that are part of the public transport system.

  4. Shopping

    In terms of shopping, Oslo offers something for everyone. In addition to a growing number of international designer brands such as Louis Vuitton, Gucci, Hermés and Burberry, there is a particularly good selection of outdoor clothing, watches, lifestyle shops, vintage, sustainable clothing, design and much more. What is best, you really don’t need an entire day for shopping as the main shopping areas are close to each other. See our high end shopping guide here. 

    Michelin star restaurant Maaemo. Photo: VisitOSLO / Anders Husa
  5. The food

    What would a holiday or trip be without food? Regardless of your preferences – seafood, French, local, fine dining, Asian – there is more than plenty to choose from.

    For visitors on a schedule, restaurants at the Oslo opera house, Ekeberg and Frognerseteren offer a great opportunity to combine sightseeing with a great dinner or lunch. If you are looking for seafood, restaurants Fjord and Tjuvholmen Sjømagasin have great menus and wine lists. Summer-only restaurant Solsiden (the sunny side) is a popular classic among the locals for a reason: it’s one of the best seafood restaurants in town.

    For those looking for Michelin star or near Michelin star level experiences, there is an option for any occasion: Maaemo for the ultimate Michelin experience, Kontrast with their modern Scandinavian take on fine dining or Statholdergaarden for those who prefer classical gourmet.

  6. It doesn’t get much more down to Earth than this

    Those of us that are used to travelling know that queues and ever-tightening security comes along with it. So visiting buildings of importance, museums and other attractions usually comes with thorough security. In Oslo, you are actually able to for example take a stroll in the same park that surrounds the Royal Palace, the King’s and  the Queen’s majestic home, without it creating a police alert. There is security, but you won’t get into trouble by snapping selfies in front of the palace. Or perhaps you’ll walk past one of the top politicians on Karl Johans Gate, next to the Parliament House, without any sign of their position.

Guide to luxury shopping in Oslo

Looking for shopping tips? The luxury shopping scene in Oslo is just like the city itself: compact, yet it offers something for everyone.

While most visitors associate Oslo with nature, the Viking ship, the Holmenkollen ski jumping tower or a blooming architecture scene, the city has quickly become also a great shopping destination.

The best thing about shopping in Oslo is that all luxury brands are located in a small area right downtown, between Karl Johans gate and Nedre Slottsgate. As with all shopping in Norway, it’s good to keep in mind that most shops are closed on Sundays. Most high-end stores open at 10AM and close at 6 PM Monday to Saturday.

Nedre Slottsgate is the heart of Oslo’s luxury shopping district.

Here are our top picks for designer shopping in Oslo:

  1. Hermés 
    Famous for its scarves, handmade handbags and other leather accessories, the iconic French brand is located in Nedre Slottsgate 15. The two-storey store offers a nice selection of goods for men and women, including items from the Hermés ready-to-wear collection. If you are looking for a specific item, I would recommend that you contact the store before your arrival – the sales associates are very helpful.
  2. Louis Vuitton
    The classic French luxury brand is located in Nedre Slottsgate 13. You’ll find mostly handbags, leather accessories, scarves and shoes for men and women in this store, but if it’s something in particular you are looking for we recommend you give them a call in advance to learn if they have the item available in store.
  3. Burberry
    You’ll find the British luxury fashion house in Nedre Slottsgate 9. The store has a selection of handbags and other accessories, scarves and a nice selection from their ready-to-wear collection, including the classic trench coat in various models.
  4. Bottega Veneta
    Next door to Burberry is Bottega Veneta, the Italian luxury brand known for its woven leather handbags. The store has a selection of handbags, shoes and other accessories. Their address is Prinsensgate 21, however the entrance is on Nedre Slottsgate side.
  5. Saint Laurent
    Saint Laurent is ne of the newcomers in the Oslo luxury shopping district. The store has a particular focus on handbags, however you’ll find a selection of shoes and other accessories as well. Address: Nedre Slottsgate 13-15.

    Jimmy Choo is one of the newcomers in Oslo.
  6. Jimmy Choo
    Opened late summer 2018, Jimmy Choo is one of the latest additions to the Oslo designer scene. The store carries a wide range of shoes and some handbags and accessories as well. The store is located in Nedre Slottsgate 17.
  7. Balenciaga
    The Spanish designer brand is one of the new brands that have opened a store in Oslo during the last couple of years. In this store you’ll find handbags, shoes, accessories and a selection of clothing from their ready-to-wear collection. You’ll find Balenciaga in Nedre Slottsgate 8.
  8.  Moncler
    The Italian luxury lifestyle clothing brand has a small Genius store in Nedre Slottsgate 13.
  9. Gucci
    A luxury fashion district would not be complete without this iconic Italian brand. The store carries a good selection of handbags and other accessories, as well as ready-to-wear for men and women. Nedre Slottsgate 8.
  10. Isabel Marant
    In Prinsensgate 22, you’ll find the brand synonymous with Parisian chic. The store carries ready-to-wear, shoes and accessories. IMG_4204
  11. Vincci
    Located in Akersgata 20 (behind the Norwegian Parliament house Stortinget), Vincci is a multi-brand boutique that carries luxury brands such as Céline, The Row, Chloé and Manolo Blahnik.
  12. Kamikaze
    While the iconic Italian designer house Salvatore Ferragamo doesn’t have a brand store in Oslo, you’ll find a nice selection of their shoes and handbags for women at Kamikaze, in Prinsensgate 21. They have specialised in luxury shoes, and in addition to Ferragamo, they carry Christian Louboutin, Les Petits Joueurs and Gianvito Rossi.
  13. Høyer
    On the second and third floor in the high-end shopping center Eger (Karl Johans gate 23B) you’ll find Høyer, a large multi-brand store. Their top floor is dedicated to international luxury brands such as Lanvin, Fendi, Loewe, MaxMara, Givenchy and Valentino.
  14. Valentino
    For the luxury fashion friend, there is more to come: Valentino is opening a store in Nedre Slottsgate, right next to Gucci (updated October 2018).

Oslo Airport Gardermoen transport guide

Oslo Airport Arrival Transport to City
Continuing your journey from Oslo Airport Gardermoen is easy. Photo: Avinor.

Oslo airport is located some 50 km (30 miles) outside of Oslo, and was opened in 1998. Since then, the airport has been through a significant expansion, also in terms of services. The airport offers a range of transport options to travellers from near and far.

Private driver / chauffeur

For a stress-free ride all the way to your hotel door, choose a private car or limousine. Many of them offer fixed rate transfers. Oslo Chauffeur Service  and Private Driver offer various car types depending on your need. A car ride from the airport to the city center takes approximately 30-45 minutes. The cost of private driver services vary, but typically start at 2500 NOK for one way (about USD 300).

Car rental

You will find several car rental companies in the parking facilities. Read more on Avinor website.


Most taxis operate with a flat fee from the airport to Oslo city center, but we recommend that you always check this before you start your ride. You will find taxis outside the terminal. Prices for a taxi ride vary by company, time of day and number of passengers, but the cost of taxi from Oslo airport to city centre typically starts at 800 NOK for 2 people during the daytime on a weekday.


In addition to the national railway operator NSB, the privately owned airport express train Flytoget operates between Oslo Airport and Oslo city (and beyond). There is direct access to both train operators from the terminal building. Flytoget leaves every 10-20 minutes, but late at night every 30 minutes. Trains to the city center take some 20 minutes. One way tickets are around 110-200 NOK, depending on which company you choose.


There are several bus companies that operate between the airport and Oslo city, and many of them cater for areas outside the city center, so do make sure to check before you get onboard a bus. SAS Flybussen operates between the airport and the city center. You will find timetables and can purchase tickets in the terminal. Busses take up to 1 hour to reach the city center. One way tickets are around 200 NOK.

How to Get Around in Oslo – Taxis, Public Transport and More

Oslo tram Aker Brygge
Photo: Ruter

Oslo is a fairly compact city with an extensive and efficient public transport system. This means that you’ll likely reach your destination on a train, bus, tram, a ferry, the underground, but more options are available.

Uber in Oslo

While ride-hailing apps such as Uber are under scrutiny in Norway, you can still get an Uber Black, Lux or XXL.

Uber X, Uber POP and Uber Pool are currently unavailable in Norway.

Public Transport in Oslo

The public transportation in the Oslo region is operated by a company called Ruter. The most convenient way to purchase tickets for public transport is through their app called RuterBillet, which is also available in English.

You can purchase single tickets or period tickets (24 hours, 7 days and 30 days) for yourself and your travel companions in the app – be aware that everyone travelling with Ruter is required to have a valid ticket on them, not on the phone of someone else on the other side of the town. The Ruter tickets are valid on local busses (red ones within Oslo, green ones outside the city borders), trams, the underground, some fast ferries (those operated by Ruter are clearly marked) and trains within the chosen zone. Read more on Ruter’s website.

Did you know that the underground – T-bane – takes you all the way to Frognerseteren, which offers a breathtaking view over Oslo?

Oslo Ferry Town Hall
Photo: Ruter/Fartein Rudjord


A large number of taxi companies operate in Oslo, and prices vary. Taxi app Mivai has several companies on their platform, which means that you will be able to compare prices while ordering.

Oslo Taxi is one of the biggest taxi companies and has their own app in addition to booking possibility on their website.

Another taxi booking app is NorgesTaxi, which also allows Paypal payment in their app. You can pre-book transfers on their website, also airport transfers. In addition to Oslo, NorgesTaxi are present in Bergen, Trondheim, Stavanger.


Rental car

Prefer sitting on the driver’s seat? Most international car rental companies are present in Oslo. However, be aware that the inner city area is very compact and offers relatively limited parking possibilities. Hotels, especially those in the city center, also often have limited offering for parking.

Oslo City Bike (Bysykkel)

As a compact city, it’s possible to explore Oslo by foot or bicycle. There are some bicycle rental places. wWe recommend you ask your hotel, as many hotels actually offer free bikes for their guests. The locals and many visitors love exploring the city by Bysykkel, the Oslo city bike. For 49 NOK a day, you have access to unlimited number of bike rentals (do note: one ride is maximum 45 minutes). The network of stations for rental and drop-off is extensive. Real-time updates for availability can be found with the Bysykkel app which is required for renting a bike.

The Bysykkel season continues until now and ice cover the streets, and begins again when the winter has literally melted away. In other words, it is closed from some time in December to approximately April.


Looking for tips on airport transfer from or to Oslo Airport Gardermoen?

Read our Oslo Airport Gardermoen transport guide