Helsinki is not one of the cities listed on every traveler's bucket list for Europe.
Maybe it's just too far from the “hot spots” everyone goes to and it has the reputation of being ridiculously pricey (which it definitely is if you are as much into wine as I am. It's fine if you aren't).
Since I am genuinely interested in overseen places I booked my flight to see the Helsinki Design week and found: the Abattoir.
In Finland, light is more valuable than in many other places. There's always too much too little.
Well, this is what people told me because I went in September where day and night both have a “regular” length. But I still found a city, which is completely adjusted to a lack of light. Almost every shop has a bright neon sign, even official institutes like banks or post offices (that will also have to state their name in Finnish and Swedish, so there are many letters so make signs of).