This bridge is made from trees that fell over in the last wind storms. The only non nature parts are the handful of nails to secure the crossboards to the runners underneath. The bridge is 6 foot wide and stong enough for just about anything to cross it.
This fence is similar in construction, but no nails were needed for this one. The sections are 12' and the posts are about 3' high.
More additions coming soon, keep checking back to see what I am up to next :)