This is one of two oak trees (ring-cup oaks) preserved at the Yamashita residence in Nagasaki City's Eri-machi.

According to the previous owner who was stationed in Sasebo city at the time of the atomic bombing, "The sky in the direction of Nagasaki became a deep red, and a booming sound could be heard." Upon returning to Nagasaki he found six members of his family had been killed.

The previous owner had often played in the tree as a child and had a great affection for it. He regularly pruned the tree and attached a supporting pole so that it would not be blown over in the event of typhoons, and did all he could to preserve it.

The previous owner's strong feelings towards the tree were handed down to his son, and it has been carefully preserved.