Here is a note from a video game:
Go through the fields.
Turn east for half a mile.
It's just past the big rock on the right.
I am not sure about the meaning of the second line. The official Russian translation sounds like Go half a mile and turn east, but shouldn't it be Turn east and go half a mile, with turning east being the first action and going half a mile (eastward) the second one? The preposition for seems to me the purpose of the turning, which is to go half a mile.