Old barn boards and beams can make some wonderful furniture too ... plane down and go for it!!
Also, I used reclaimed barn boards as trim when restoring my 150 yo farm home. Again, planed, then routered it to make age appropriate trim. The nail, worm and knot holes added to the rustic look. It looked like it belonged, better than the new stuff if it had been used.
In my mud room, I have a large barn beam for a window sill. Also, as a bench another runs the length in a lost space between the garage door and verandah door. Sits at just the right height to take your boots off, and boot trays fit in underneath.
Here's to good luck in your quest!