When in April are you going? The Swedish celebrate Valborg on April 28th to May 1st and it is the end of winter celebrations. If you are there at that time I would strongly suggets getting the train up to Uppsala, which is about 30 miles north and an easy train ride. I lived there for a year and it is the student capital of Sweden (don't let that put you off) and the town goes crazy for Valborg (fancy dress boat races, street parties, concerts and tonnes of beautiful women in a party mood). It is something I will never forget and strongly recommend experiencing.