The Sasayama site is located at Nakajo,Tokamachi City,Niigata Prefecture.

The site is situated on the right bank of the Shinano River terrace in central Japan,

170 to 180 meters above sea level.

The excavations were carried out seven times during 1980 to 1985, by the Board of Educations of Tokamachi City, prior to the construction of the municipal baseball and athletic ground. The total excavation area extended to 15460 square meters. The excavations uncovered the settlement of the Middle Jomon Period and the Medieval Period.

Middle Jomon Period (4,500~3,500y.B.P)

The features uncovered are 112 fireplaces, 6 pit 39 buried jars. The cluster of fireplaces are circularly arranged,and it measures 110 meters in diameter.

Most of potteries belong to the middle part and the latter half of the Middle Jomon Period. In particular,”Kaen type”vessels(火焔型土器)represent the potteries of the Middle Jomon Period. The characterristic elements of this vessel include, for instance, flame-shaped form, four cockscomb-shaped grips on the rim, spiral patterns decorating with raised clay bands on the body surface. Most of vessels of this type have been found in the middle basin of Shinano River. “Kaen Type” vessels are unearthed along with “Okan Type”vessels(王冠型土器).The denomination of this vessel derived  from a Japanese equivalent word “crown”.

Since they have been found in increasing numbers, with soot and carbonized materials adhered to the inside, the vessls are thought to have practical wares for daily use.

The excavations yielded 9331 lithic artifacts, including allowheads(82) , points(20) , drills(9) , scrapers(63) , chipped axes(952) , polished axes(145) , pebble tools(5) , grinding stones(823) , grinding slabs(73), floats(3), stone rods(7), pendants(3), cores(58), flakes(6928), etc.