"Those bogs are in the middle of Finland."
Translation:Nuo suot ovat keskellä Suomea.
I already responded to your other comment about this same thing lol. The original translation and what you said are both correct. So if it doesn't accept your answer, report it, but the original is still correct.
Here's a source about these: https://uusikielemme.fi/finnish-grammar/syntax/constructions/finnish-prepositions-prepositiot-partitiivi/ read the part 2.2. Pre- & Postpositions