Surströmming is another:

Here is a description of surströmming I found on the web:

"If you try surströmming, or fermented Baltic herring, we are confident that you will never forget it. It is sold in cans, and when you open them a strong, foul smell is released, the result of a fermentation process.This method of preservation was invented long ago, when brining food was quite expensive due to the costs of salt. When fermentation was used, on the other hand, just enough salt was required to keep the fish from rotting. Surströmming is served with boiled potatoes and onions and often rolled into a slice of tunnbröd, a type of thin, flat unleavened bread.  Although lots of people do not like it, you have to eat it a couple of times before you really appreciate the taste, there is a hard core of surströmming devotees, most of them in the north of the country."
Surströmming is often accompanied by aquavit and beer.

My vacation pictures from Denmark and Sweden