The northern terminus of the Norwegian railway, Bodo, Norway, is slightly north of the Arctic Circle (watch for the marker just before the train pulls into town) and 525 mi/845 km north of Oslo.
There's not much to do in Bodo, although the modern cathedral is interesting, and the Norwegian Aviation Museum is worth a look (http://www.luftfart.museum.no). Nonetheless, the train trip there is a good way for Eurail pass holders to see a bit of tundra.
Bodo is also very popular in summer—it's o...