Ulleung-do (also spelled Ulreungdo; Korean pronunciation: [ulːɯŋdo]) is a South Korean island 120 km (75 mi) east of the Korean Peninsula, formerly known as Dagelet to Europeans. Volcanic in origin, the rocky steep-sided island is the top of a large stratovolcano which rises from the seafloor, reaching a maximum elevation of 984 metres (3,228 ft) at Seonginbong Peak. The island is 11.3 kilometres (7.0 mi) in length and 12.4 kilometres (7.7 mi) in width; it has an area of 73.15 km² (28.24 sq mi).