The Sanmyōji Kofun is located on the south side of the Mukaiyama Hills that spreads out to the north of central Kurayoshi.

In addition, there is an enclosure made of stone slabs adjacent to the back wall of the burial chamber.

This antechamber construction is more commonly found in the Kyushu region of Japan.

The burial chamber is known to have been open since ancient times, so no grave goods have been recovered.

[2] The tumulus is located a ten-minute car from Kurayoshi Station on the JR West San'in Main Line.