A museum dedicated to the salmon and to general fauna around the Mörrum river. This is relatively new and didn't exist when I visited so I have no personal experience. It is open the same months as the fishing is allowed (see tip).
Mörrum is one of Europe's most famous fishing places so this is what you do here. Don't worry about the dark waters, that's just because the river originates in the highlands in Småland to the north, where there is a lot of spruce forests it has to run through. Not only salmon and trout can be caught but also fish like perch and pike. You need to buy a fishing license at "Sportfiskekontoret" in the village and you can be off. The fishing period is 1 April to 30 September and for the opening days, there is a draw as to who gets licenses. If you want to make sure to get a place, send your requested dates here:
Mörrums Kronolaxfiske, Box 26, 37521 Mörrum, telephone +46 (0)454-50123.
If you are a real fishing enthusiast, you can also go to nearby Svägsta and visit the ABU factory where the well-known Swedish fishing equipment (Japanese owned today I believe) has been made for a long time.
Equipment: Bring your own or rent from local shops. You can not fish from boats, only the riverside.