Comment by h3half

I think your final sentence would be a more specific/more correct to say "five acres away", but in reality I don't think I've ever heard anyone use a furlong as a serious unit in conversation.

I have heard sentences like "the property line is two acres into the woods" and it was understood that he was using acre like you might use "block" in a city - "the property line is two acre widths into the woods". As you say, that's just a furlong, but I doubt either of us knew that at the time.