The tumulus is located on a low hill ridge that is 70 meters higher than the alluvial area at the eastern edge of the Nara Basin. It is a keyhole-shaped tumulus constructed at a great natural location that faces north. The entire length is about 130 m, the diameter of the round rear is about 80 m and the width of the square front is about 50 m. The excavation was conducted in 1961 and 1966 and found fukiishi (small stones covering a mound), rows of cylindrical haniwa, arrow holder haniwa and armor haniwa in the round rear. Jasper arm ornaments (hoe-shape stone, wheel-shape stone, ishikushiro (stone bracelets) and talc pots with a base were also found in the clay chamber in the round rear. A large amount of weapons such as iron swords and kanto (literally ring top) swords (single kanto, bronze kanto), as well as battle gear and lacquered leather shields, were found outside the coffin.
The gold inlay flower-shaped kanto sword with the inscription of中平 (「中平」銘金象嵌花形飾環頭大刀) is the oldest relic with an inscription of the year of creation in Japan. It seems that the blade part was made in China and was altered, while the kanto part was replaced by one unique to Japan and developed based on sanyo kanto with chokkomon (a complicated pattern comprised of straight lines and arcs) and ryumon (dragon) patterns are applied. Other artifacts excavated include 13 kanto swords and swords with wooden handles, over 25 iron swords and lances, 261 bronze arrowheads, 1 set of leather armor and seven bronze vessels in the shape of tomoe (a pattern of curled tadpole shapes inside a circle). A total of 62 beads, 45 stone arrowheads and 13 pot-shaped stone vessels were also excavated. While the total of 51 jasper arm ornaments ranks 8th across the country in terms of quantity excavated from one site, the total of 26 items comprised of bronze arrowheads, pot-shaped stone vessels and hoe-shaped stone objects ranks at the top.