The Gochang, Hwasun and Ganghwa Dolmen sites contain the highest density and greatest variety of dolmens in Korea, and indeed of any country. The Hwasun Dolmen Site (31 ha) is situated on the slopes of a low range of hills, along the Jiseokgang River. The Ganghwa Dolmen Sites (12.27 ha) are on the offshore island of Ganghwa, on mountain slopes. The Gochang, Hwasun and Ganghwa Dolmen Sites preserve important evidence of how stones were quarried, transported and raised and of how dolmen types changed over time in northeast Asia. The Gochang Dolmen Museum, Hwasun Dolmen Site Protection Pavilion and Ganghwa Historic Museum provide information about each dolmen site to visitors.