There is a slightly less than two-meter high, 9.75-meter and 12.5-meter Kukei-dan (rectangular platform) with stuck stones (bricks) located on the top of the back circular part and porous Tsubogata doki earthenware (Niju Koen tsubogata doki [earthenware in a shape like double rim pot]) are placed squarely surrounding the foot of the platform.
後円部の頂に高さ2メートル弱、１辺9.75×12.5メートルの貼石のある矩形壇があり、また方形に巡る有孔の壺形土器（二重口縁壺形土器）が壇の裾周りに巡らされている。