Jomon pottery and obsidian from the Japanese Archipelago, as well as pottery characteristic of Jeju Island, have been found along the southern coast, at Dongsam-dong(Busan) and Yeondaedo Island(Tongyeong). Chinese jade has also been found at Huam-ri(Seocheon). This suggests that the Neolithic people sailed across the seas to Jeju Island, the Japanese Archipelago, and the Chinese mainland in log boats like the one found at the Bibong-ri site.