With a commemorative ceremony for the 2,600th year of the founding of Japan held in 1938, research on the land of Jingu Gaien (the Outer Gardens of the Meiji Shrine) was conducted under the direction of Masao SUENAGA, and discovered that remains of a large settlement from the late to last of Jomon period was buried under the ground and as well found a giant evergreen oak was buried in a state of standing and spreading out its roots in 16 square meters.
なお、1938年（昭和13年）から挙行された紀元二千六百年記念行事に伴い、末永雅雄の指揮による神宮外苑の発掘調査が行われ、その地下から縄文時代後期～晩期の大集落跡と橿の巨木が立ち木のまま16平方メートルにも根を広げて埋まっていたのを発見した。