Östersund, third largest settlement in Sweden per population (750), has not yet appeared in the comic beyond being named as the birthplace of Emil Västerström. The author also mentioned in a comment that he was deployed "a bit futher north from Mora" while working as a cleanser, which might happen to mean Östersund or its vicinity as well.

The World Map shows a train line leaving Mora northbound through Östersund and on to Skellefteå and Luleå, but there seems to be a stretch of Silent Lands halfway to Östersund, rather than the line having been built entirely though cleansed areas.

The Known World
Countries: Denmark (capital: Rønne) - Finland (Saimaa) - Iceland (Reykjavík) - Norway (Aurland) - Sweden (Mora)
(See the countries' individual pages for a more extensive list of their settlements.)
Other: Öresund Bridge - Shetland and various other small islands

The Silent World
Actual locations: Seas and Ocean - Baltic Sea
Transport therein: Dalahästen - The Cat-tank - The Paddlewheeler - The Timbercruiser