Artist impression of the seventh century Koyamada Burial Mound Moat
Image credit the Archaeological Institute of Kashihara

Kazuto Tsukamoto, Staff Writer for the Asahi Shimbun, reports last week that archaeologists in Japan have unearthed the remains of a possible mid-seventh century imperial burial mound (kofun 古墳). The remains of the Koyamada Mound were discovered on the site of a school in the Askua area of Nara Prefecture, central Japan. Asuka was one of the early capitals of Japan before being relocated to Nara and then Kyoto (see our earlier feature, Asuka, Japan: An introduction to its megalithic sites).

“The mound is highly likely the first burial site of Emperor Jomei (593-641), described in the ‘Nihon Shoki’ (The Chronicles of Japan) as the place where his body rested until it was later transferred to another location,” said Fuminori Sugaya, the director of the Archaeological Institute of Kashihara, Nara Prefecture. The researchers made the estimate based on the ruin’s location, size and unique construction method.

The excavation site contains what is believed to be part of a moat lined with boulders along one of its slopes, according to the researchers. The remnants of the moat measures 48 meters in length and 3.9 to 7 meters in width. While 40-centimeter quartz diorite boulders line the northern slope of the moat, the bottom is covered with stones measuring 15 cm to 30 cm. The southern slope is covered with flagstones made of two-step chlorite schist that are topped with special flagstones known as “Haibara,” a type of rhyolite stone, stacked in a staircase pattern. The total number of steps in some areas is 10.

Full Asahi Shimbun article here.