Ulleungdo
| NASA Landsat7 image of Ulleungdo (north oriented at top) | |
| Geography | |
|---|---|
| Location | Sea of Japan | 
| Coordinates | 37°30′04″N 130°51′23″E / 37.50111°N 130.85639°E | 
| Area | 72.86 km2 (28.13 sq mi) | 
| Highest elevation | 984 m (3228 ft) | 
| Administration | |
| South Korea | |
| County | Ulleung County | 
| Province | North Gyeongsang Province | 
| North Korea (claimed) | |
| County | Ullŭng County | 
| Province | North Kyŏngsang Province | 
| Demographics | |
| Population | 9,191 (Sep 2020.) | 
| Pop. density | 126/km2 (326/sq mi) | 
| Ethnic groups | Koreans | 
| Korean name | |
| Hangul | 울릉도 | 
| Hanja | 鬱陵島 | 
| RR | Ulleungdo | 
| MR | Ullŭngdo | 
| IPA | [uɭːɯŋdo] | 
Ulleungdo (Korean: 울릉도; pronounced [uɭːɯŋdo]), also spelled Ulreungdo, is a South Korean island 120 kilometres (65 nmi; 75 mi) east of the Korean Peninsula in the Sea of Japan. It was formerly known as Dagelet Island or Argonaut Island in Europe. 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 9.5 kilometres (6 mi) in length and ten kilometres (6 mi) in width; it has an area of 72.86 km2 (28.13 sq mi). It has a population of 10,426 inhabitants.
The island makes up the main part of Ulleung County, North Gyeongsang Province, South Korea, and is a popular tourist destination. The main city of Ulleungdo is the port of Dodong (도동; 道洞), which serves as the main ferry port between Ulleungdo and the South Korean mainland. After tourism, the main economic activity is fishing, including its well-known harvest of squid, which can be seen drying in the sun in many places.