I was lucky enough to know someone who's property had 4 barns that were on the virge of falling over.
I removed wood from the barns I needed, some wood was just inside the barns. The thick pieces with holes going around the table were actually old telephone poles (horizontal section).
The plans were straight forward, but prepping, cleaning, sanding the wood from an old barn was the most time consuming. Also hardly anything was straight or square!