These dolmen are located on Ganghwa Island, Ganghwa County, Incheon. They are located on the slopes of mountains and are thus higher in elevation than their counterparts. These dolmen are believed to be earliest ones made because the dolmen groups in Bugeun-ri and Gocheon-ri resemble the early dolmen. However, this has not been conclusively proved. A notable dolmen at Ganghwa is a northern/table-type dolmen where it was believed ancestral rites were performed. It is the biggest stone in South Korea with measures of 2.6 × 7.1 × 5.5 meters, but it has only two supporting stones. Combined the supporting stones and the capstone weigh between 150 and 225 tons.