Sido Island is located 5km south of Ganghwado Island, 3km to the east of Jangbongdo Island, and is neighbored by Sindo and Ttiseom islands to the east and west respectively. It is connected to Sindo Island via Yeondogyo, a 579 meter-long bridge that was constructed in 1992. Sido is also known as ‘Salseom Island’ and ‘Hwasalseom,’ which means ‘arrow’ in Korean. It is said that during the late years of the Goryeo Dynasty, the military (then led by famous generals Choi Yeong and Yi Seong-Gye) practiced archery at the foot of Mt. Manisan while using the island as the main target. Since many earthenware and shell instruments were excavated from Sido, it is believed that the island has been inhabited ever since the Neolithic era. The island has unique topographical features. Wide tidelands can be found on all sides and to the north and south, there are rocky coasts and low hills. The central area is comprised of flat fields filled with oak trees bearing acorns and the more mountainous areas are dotted with pines and oak saplings. Residents here work primarily as a fishermen and farmers. The island is famous for its high-quality grapes and octopus and shellfish that are caught from the islands wide tidal flats.