Where to Start my 3-week Boat/Bus/Train Scandinavia Trip

Balkan trip from Helsinki to Scandinavia? What are you actually planning? Of course you can travel between Balkan and Scandinavia, but they are nowhere near each other.

I guess the OP meant Baltic, not Balkan ;)

I do not know the details of the RS itinerary, but if you want to visit Norway, Copenhagen is a major detour.
It seems more efficient to go "straight" from Stockholm to Oslo, and leave Copenhagen for another trip.

@Badger & @Balso, yes, I meant Baltic, thanks for the correction.

I will spend April in the Balkan countries & May in the Baltics. Instead of flying back to the US I’m considering to continue my journey to Scandinavia in June for 3-4 weeks but not quite sure yet whether to go to Stockholm first or Copenhagen.

Are you ending your Baltic time in Estonia, Latvia or Lithuania?

@acraven, (I was going to end it in Tallinn, Estonia but added) Helsinki because of its proximity.

OK. In that case, based on my own trip research (no actual experience yet), I'd ferry from Helsinki to Stockholm, see what I wanted in Sweden, and then travel overland to Oslo, Then finish up in Denmark if you don't run out of time first. (I certainly would.) Or you could travel Helsinki - Stockholm - more of Sweden - Copenhagen - more of Denmark and leave Norway for a later trip.

The only disadvantage I'm aware of with either of those routes is that the most beautiful part of the ferry trip between Helsinki and Stockholm is on the Swedish end, as you travel through the Stockholm Archipelago. Traveling east, you see that before nightfall; traveling west, I think you may be asleep for much of that time.

But surely you'll get input from other folks soon. They may well have more/better information.

As you've described your trip so far, you will be OK, but just in case you have a lot of free time and have the same reaction I did when I dug into guidebooks for northern Europe (a month here, a month there, 3 weeks there...), keep in mind that unless you are traveling on an EU passport, you are limited to 90 days in the Schengen countries within any rolling 180-day period. Most of Europe is part of the Schengen area, though most of the Balkans are not. You need to be sure you don't have more than 90 days altogether in Greece, Slovenia, Estonia, Latvia, Lithuania, Finland, Sweden, Norway and Denmark--plus all the rest of western Europe except for the UK and Ireland. Croatia is getting closer and closer to joining, too.

The Baltics makes a lot more sense! In that case I agree that a good start is the overnight ferry from Helsinki to Stockholm. Don't sleep late though, you don't want to miss the morning cruise through the archipelago.

Then stay a couple of days in Stockholm. After that, well it depends. How much time do you have and what do you want to see and do?

@Badger,
I have 3 weeks (max. 4 weeks) for Scandinavia with focus on Norway but wouldn’t want to miss Denmark & Sweden. I like light-moderate hiking, paddleboarding, photography, food trips & volunteering (eg. I walked & gave baths to dogs in Refugio Holbox, Mexico).

@acraven, thanks for reminding me of the 90-day tourist stay in EU.

3 weeks is plenty of time. A popular way to see Scandinavia starting in Stockholm is Stockholm-Copenhagen-Oslo-Bergen, but you could add other stops as well. A visit to Gotland e.g. And I would recommend Gothenburg as well. Or maybe somewhere a bit more north? It can also make sense to end in Copenhagen as it is the largest airport in Scandinavia with direct flights to many North american cities.

Hiking is popular especially in Sweden and Norway and there are trails more or less everywhere and the options are varied, from short and easy routes to the 1300 km Gröna bandet. And there are certainly options for food experiences, like the importance of Fika in Sweden. Regarding photography, is there any perticular genre you enjoy? Architecture? Landscapes? Street?

@Badger, thanks for the suggestions.

I take landscape, architecture, food, people photos.
After visiting the touristy spots I like to just meander in alleys, boardwalks, markets, talk with locals and other tourists.

@Badger, a Norwegian I met in Antarctica said if I ever go to Norway make sure to visit Lofoten or Senja. Could that be in my 4th week?

Maybe, Lofoten and Senja are certainly beautiful areas but they suffer from overtourism in my opinion. Especially since they don't stand out that much, there is no shortage of beautiful areas in Norway.