About 65,500 people live on the island. With an area of . It covers most of Ganghwa County, a division of Incheon Municipality. About half of the island's population lives in Ganghwa-eup, Ganghwa Town, in the northeastern part of the island. The island's highest point is Mani-san, above sea level. The island measures long and wide, and is the 4th largest island in South Korea.