Where does “Käkisalmi” come from?

Käkisalmi (Finnish) comes from Finnish Salmi, from Finnish -lä, from Finnish -as, from Proto-Finnic -s, from Proto-Finno-Ugric -s.

Ancestry of “Käkisalmi”, step by step

Käkisalmi traces back through two separate lines of ancestry.

via Finnish Salmi

StepLanguageWordMeaning
1FinnishSalmiA town in Russian Karelia
2Finnish-läFront vowel variant of -la
3Finnish-asForms some adjectives; Forms some nouns
4Proto-Finnic-sForms nouns
5Proto-Finno-Ugric-s

via Finnish käki

StepLanguageWordMeaning
1Finnishkäkicuckoo
2Japanesea persimmon, especially the Japanese persimmon;...
3Old Japanese
Every word from Proto-Finno-Ugric -sEvery word from Finnish -läEvery word from Finnish -as