Visiting Oslo via an over night trip by the color line ferry is a very nice one. You start in Kiel, usually at 2 pm, passing the Kieler Förde, entering the open sea towards Norway. After enjoying nice food, duty free shopping, sports and cool entertainment on board next morning the ferry arrives in Olso at 10 am. Now you have 4 hours to spend in a beautiful nordic capital - in case you know where to go!
If it is your first trip to Oslo I recommend the guided tour by bus, hopping from one selected spot to the next, filled with stories all around Oslo and Norway in general. The stops are:
If you already are at your second trip or you are not very interested in norwegian history you can just chill at the marina, enjoy a starbucks coffee and visit some nice boats. Here I recomend to rent one of these e-scooters so you just are a bit faster in the neareby marina and can use your precious time for relaxing and sitting on the dock.
Third option is simply stay on board and enjoy the silence and the sundeck for your own - having a stunning view towards oslo and into the Oslo-Fjord at the same time.
Its up to you and your preferences!
Stay tuned for my recommendations to prepare your trip by the ferry and what to do best on board!