There are many great fjords to explore in Norway. The most well-known fjords are located in the lower half of Norway. These include Geirangerfjord, Hardangerfjord, Sognefjord, Naerøyfjord, and Lysefjord. The upper half of Norway also has great fjords, like Lygenfjord and Nordfjord. But to access these, you need to fly into Tromsø since this area is a 21-hour drive north of Oslo. Norway truly is a long country. While each of the fjords has its own special characteristics and beauty, this guide will focus on Sognefjord/Naerøyfjord and Hardangerfjord because they are the most accessible from Oslo.
You've probably heard of FjordTours, which runs tours such as "Norway in a Nutshell." Most travelers should book with a company like this because they make it convenient. I've researched booking all the train, boat, and transfer components individually and it is absolutely doable. You may even save a little money. But there are so many moving parts that I don't feel it's worth the headache. You are on vacation, so having one point of contact for everything is less stressful. Keep in mind there is a lot of flexibility in this tour. If you want to stay a night at a port of call, you can do so if you let them know and book the proper dates of each component on their excellent website. They offer hotel stays and activities at many stops. Then, the next day you can catch the next boat and continue on your journey. Or, you can do the entire trip in one day, albeit a very long and exhausting day.
I modified my tour because I wanted to see more fjords. I took the Norway in a Nutshell only one-way west to Bergen. Then, I returned the next day via Hardangerfjord east to Oslo. It was two full exhausting but wonderful days. Was it expensive? Yes. But it's a bucket list item and well worth it. Part, or maybe most, of the reason you're in Norway is for the fjords.
There are even more options in these tours for hikers. For example, you can do the Norway in a Nutshell tour and add in a side-trip south to Lysefjord and hike to the famed Pulpit Rock. This is a 3-day minimum due to the distance you need to travel. The hike itself to Pulpit Rock is a 4-hour roundtrip, but standing out on that famous rock gives you the rare chance to look down as opposed to looking up from the water. Or, when in the Hardangerfjord area, you can opt to hike the famed Trolltunga rock (the troll tongue). This popular hike is on most people's bucket list despite being in the middle of nowhere and a 17-mile strenuous round trip. The views from here are legendary. Ten months out of the year, hiking with a guide is mandatory.
Anyway, let's get into the details of the Norway in a Nutshell tour from Oslo. This is one of the few tours that operate year round. First, you'll take an early ride on the Bergen Railway from Oslo to Myrdal, enjoying mountain views. Then, you'll transfer to the famous Flåm railway. This is the most scenic section of the rail trip. A neat surprise for me was passing Kjosfossen, a gorgeous waterfall. If you're lucky, music starts playing and a dancer appears on a cliff by the falls. Once you get to Flåm, you'll board a boat and cruise through Aurlandsfjord. At the midpoint of your cruise, you'll turn down Naerøyfjord, which is actually part of Sognefjord. Naerøyfjord is one of the narrowest fjords, so you'll enjoy being surrounded by high mountains that seem pretty close. It's dramatic and you'll take photos aplenty. The cruise lasts about 2 hours. Then, the boat arrives at Gudvangen and you will board a bus and travel through small villages and more beautiful landscape. Once you get to Voss, you'll hop aboard the Bergen Railway and head further west to Bergen for the night. You'll get to Bergen at 8:00PM, 13.5 hours from when you first boarded the train in Oslo. Or, if you are doing this trip as a one-day loop, you will go the opposite way and head back to Oslo and get in at 10:30PM.
Bergen is a beautiful town. Keep in mind you'll be getting in relatively late so you may want to book a hotel that is near the rail station. Since I was heading out on another fjord cruise early in the morning, I just booked a satisfactory and budget-friendly CityBox hotel. If you do have some time to spend in Bergen, perhaps stay closer to Bryggen. It's a picturesque clump of old colorful wooden wharf houses. As expected, there is plenty of hiking and mountain activities here. What you may not expect is the superb quality of the restaurants here. They offer many creative and delicious selections, including fresh seafood of course.
To head back to Oslo, I recommend taking the "Hardangerfjord in a Nutshell" tour. Please note that the journey I'm about to describe is only for one-way travel from Bergen to Oslo. If doing the Hardangerfjord loop (from Bergen to Bergen), the journey is different. For the one-way trip, you'll start with an early bus ride to Norheimsund. There, you'll board the boat and cruise Hardangerfjord, which is Norway's second longest fjord. You'll depart at Eidfjord and take a bus to a stellar nature center. After that, the bus will take you to Vøringsfossen, one of the most impressive waterfalls I've seen. There are little paths everywhere so you can explore and try to get a better glimpse of the massive falls and the stunning valley. Then, the bus returns you to Eidfjord where you will board the boat again to head to Ulvik. From there, it's a bus ride to Voss, where you will board the Bergen Railway back to Oslo. When you pull into Oslo station at 10:30PM, it will have been 15 hours from when you boarded the first morning bus. A long but amazing journey.