Atagoyama Kofun (Mito)

The is a "kofun" burial mound located in the Atago neighborhood of the city of Mito in Ibaraki Prefecture in the northern Kantō region of Japan. It received protection as a National Historic Site in 1934.
Overview.
The Atagoyama Kofun is located on a river terrace on the west bank of the Nakagawa River at an elevation of 40 meters. It is a , which is shaped like a keyhole, having one square end and one circular end, when viewed from above, and is one of the best-preserved keyhole-shaped "kofun" in eastern Japan. It is also one the largest found in Ibaraki Prefecture. 
The tumulus has a total length of 136.5 meters with an orientation of northwest to southeast and was surrounded by a moat with a width of 23 meters. The tumulus is well-preserved, but the moat has mostly been filled in and is occupied by private residences. The "kofun" is named for a Shinto Shrine, and Atago Shrine located at its summit.
The interior of the tomb has not been excavated, but fragments of Sue ware pottery have been found in the vicinity in 1978 survey. Large cylindrical "haniwa" were found on the ridges and skirts of the posterior part of the posterior dome, so it is estimated that there were originally 3 to 4 rows of "haniwa". From the style of the "haniwa" it is believed to have been built in the early 6th century as the tomb of Takekashima-no-mikoto, the "Kuni no miyatsuko" of the "Nakanokuni", whose territories existed on either side of the Naka River. 
The tumulus is one of a cluster of "kofun" in the vicinity, which were not accorded protected status. The tumulus is a five-minute walk from the "Hakamatsuka 2-chome” bus stop on the Ibaraki Kotsu Bus from Mito Station.