Before the stone chambers were constructed, soft soil near the surface was removed by digging a large with approximately 8 meters wide from east to west, about 13 meters long from north to south, and over 1.5 meters deep.
石室を築造する前に、東西約8メートル、南北約13メートル以上、そして深さ1.5メートル以上という大きな穴を開けて地表近くの柔らかい土を取り除いた。