If you've only seen Stockholm in Sweden, PLEASE get out into the rest of the country and have a look. Its worth the effort, not only with fabulous scenery but also the smaller towns always have less tourists, interesting corners and from experience, friendlier people who are generally interested in where you are from and that you have taken the effort to come and visit their home town.

Kalmar is a long train trip south of Stockholm - approximately 4.5 hours on a fast trains. If you don't have a Eurail pass, it may be worthwhile considering a bus but the  train trip is worth it. There are some spectacular vistas - you know, the usual Swedish birch forests, still reflective lakes, cute farm houses -