[3] The Watanuki Kannonyama Kofun is located on a plain on the west bank of the Ino River, six kilometers east of the city of Takasaki, and is constructed facing north.

The haniwa were of especial interest, as they depict men, women, boys and girls, in various costume, including what appear to be warriors in armor and with shields, farmers and aristocrats.

The burial chamber is a horizontal trapezoidal stone-lined room in the middle of the posterior circular portion, opening towards the southwest.

The blocks weigh up to 22 tons, but as there is no source for these materials from the neighborhood of the burial mound, it was necessary for these stones to be transported from a considerable distance to construct this tomb.

The grave goods included two bronze mirrors, gold, silver and glass jewelry, iron swords, iron spearheads, fragments of armor, horse harnesses, saddles, stirrups and Sue ware, Haji ware, copper water bottles and other containers, many of which were found to be in excellent preservation.