Kind of as other said, it was buried. From what I have read archaeological finds are about piecing together good guesses. Sure some wood is rot resistant but I suspect you would be hard pressed to find wood sitting outside for 1000+ years on the ground that early civilization would find appeasing to build with. Anything is possible but I am guessing it either fell natural or was harvested by those people and they decided to build with it somewhere plus or minus a thousand years.