ASUKA, JAPAN—The Asahi Shimbun reports that archaeologists excavating a sixth-century A.D. tomb mound in Japan's Nara Prefecture believe it was shaped like a step pyramid. The tomb, which stands more than fifteen feet at its highest, once probably held the remains of the powerful clan leader Soga no Iname, who was the grandfather of three emperors. Previous digs at the site had done little to clarify the construction of the tomb, but Kansai University Archaeological Research Institute researchers were able to expose stone-lined steps that would have given the monument an unusual pyramid-like appearance. “Archaeologists and experts checked to see if there are any similarly structured tombs in Japan, but there is nothing like it," an Asuka municipal official told the Wall Street Journal. "The tomb is unique.” The archaeologists were also able to determine the tomb had a stone-lined moat.