Ulleungdo
Ulleungdo is a South Korean island, the main part of Ulleung County, North Gyeongsang Province, South Korea, in the East Sea. This island is at 37°30'N 130°52'E. The part of this island is the peak of a mountain. This mountain is a large stratovolcano which rises from the seafloor. The formation time of this volcanic mountain is between the Cainozoic Third Era and the Cenozoic Fourth Era. The highest peak of Ulleungdo is Seonginbong peak at 984 meters. The Nari Basin and Albong Basin were made by the collapsing aldera crater in the northern slope. Ulleungdo is a pentagon shaped island. The length from east to west is 10 km, the length from south to north is 9.5 km, and the total length of the seashore is about 56.5 km.