Excavation site at Daesin-ri is in front of Jidong village. Since it was excavated in 1999, it has been protected, being covered by roofed pavillion built above itafin 2008. Surveys on35 dolmens were carried out.and various types of burial chambers, burnished red pottery, spindle, pieces of stone dagger, and stone arrowhead were excavated. In particular, according to the radio carbon datingicharcoal is dated 550 B.C and the pottery was in 770 B.C. Thus it was assumed that dolmens were built between 2800 and 2500 years ago.