Originally Posted by
intuition
Some places have a original name in one language and the other language translated them, or translated parts of the name or looks like a derivation (Sandkulla - Hiekkaharju, Villmanstrand - Lappeenranta, Tavastehus - Hämeenlinna)
In few cases the coat of arms helps to remember the Swedish name. The coat of arms of Lappeenranta (Villmanstrand) has a wild man. The most peculiar case is Hartola having a crown on it. Thus the Swedish name is Gustav Adolfs (named after the son of Gustaf III who established the community).
One more example of the coat of arms. The coat of arms of Varsinais-Suomi, Egentliga Finland (”Finland Proper”) has two Swedish flags. This time you have to remember a reverse rule.