Norrland is one of three major regions in Sweden. Norrland encompasses two-thirds of the country's surface and about one-sixth of its population. Most of the major national parks in Sweden are located in the Northern parts of Norrland. The region is characterized by forests, mountains, rivers, mines, a harsh winter climate, long distances, left-wing attitudes, as well as university towns with young populations.
As elsewhere in Sweden, Swedish is of course the main language. Among older people in rural areas it is often spoken with very distinct local dialects, but all dialect speakers also speak Standard Swedish, which is also the main tongue in Sweden nowadays (including, contrary to popular belief, Scania).
As for English, it is spoken by nearly everyone, and most often fluently by those aged 12-50. Due to the proximity of the border, some people also speak Finnish. In the northern parts of Norrland, many people also speak Sami, a native language of the reindeer herders, although everyone speaks Swedish and (unless really old) English.
Connex  runs daily trains between Göteborg and Narvik, Norway with several stops, including Stockholm, Uppsala and many along Norrland. Sleeper accommodation is available. Reservations are required to use the Eurail Pass. Price for the full trip was around 450SEK on a simple seat as of 2006, and the journey took more than 24h. Stockholm - Abisko (for starting Kungsleden) was about 17h.
The city of Kiruna can be accessed by plane and is located close to the Kungsleden trail.