caves are dark = a barlangok sötétek
meaning is the same, but not exact translation / grammatical incorrect
No, Bastette. Remember, you do not use 'van' in the type of sentence you are suggesting.
I would guess that it would translate to "A barlagok sötét van".
Because you can't really fit the "-ban" information into the english sentence. "Caves are dark inside" would then require other words.