During the Koryo period (918-1392), there existed two groups of earthenware and celadon kiln sites: Kangjin-gun in Chollanam-do and Puan-gun in Chollabuk-do. To date, about 400 kiln sites have been discovered in these two areas.
In particular, some 188 kilns, the highest record in Korea, are distributed in the region of Yongun-ni, Kyeyul-li, Sadang-ni, and Sudong-ni of Kangjin-gun. Well-conserved, 98 of them were designated as historic sites by the Korean government.
Some 37 kilns remain in Yongun-ni today in generally good condition. Most of the kilns are early kilns established from the 10th century through the 11th century. Fragments that are considered to be related to the ancient Chinese kilns have been found in the kiln sites of this region.
Some 29 kilns remain in Kyeyul-li. Although some fragments of the same style as those found in Yongun-ni were also discovered in Kyeyul-li, most of the kilns date from the 11th to the 13th centuries. Many fragments of conventionalized inlaid celadon ware were found here.
Some 27 kilns remain in Sadang-ni. Of those, kilns of Tangion village dating from the early 12th century to the 13th century are representative of the Koryo ceramic kilns which were used when Koryo celadons, known for their superior kingfisher color and inlay technique, were at their peak. Some f~ve or six kilns remain in Sudong-ni dating from the 14th century. Most have been destroyed through river erosion and farming.