Occupying the southern 45% of the Korean Peninsula in East Asia, the Republic of Korea (ROK), also known as South Korea, has an area of 98,480 sq km (38,023 sq mi), extending 642 km (399 mi) NNE–SSW and 436 km (271 mi) ESE–WNW. Comparatively, the area occupied by South Korea is slightly larger than the state of Indiana. Bounded on the north by the Democratic People's Republic of Korea (DPRK), on the east by the Sea of Japan (known in Korea as the East Sea), on the south by the Korea Strait, and on the west by the Yellow Sea, the ROK has a total land boundary length of 238 km (148 mi) and a coastline of 2,413 km (1,508 mi). A demilitarised zone (DMZ), 4,000 m (13,100 ft) wide, covering 1,262 sq km (487 sq mi) and located north and south of the 38th parallel, separates the ROK from the DPRK, which comprises the northern part of the Korean Peninsula.

Over 3,000 islands, most of them off the southern and western coasts and belonging to the ROK, add another 8,600 km (5,350 mi) of coastline.

The ROK's capital city, Seoul, is located in the northwestern part of the country.

Elevations in the southern part of the Korean Peninsula are generally lower than those in the north. Only about 30% of the ROK consists of lowlands and plains. The principal lowlands, all bordering the Yellow Sea along the west coast, include the Han River Plain, near Seoul; the Pyongtaek and Honam plains, south of the capital; and the Yongsan Plain in the southwest. Mt. Halla (1,950 m/6,398 ft), on volcanic Cheju Island, is the nation's highest point, while Mt. Chiri, or Chii (1,915 m/6,283 ft), is the highest point on the mainland.

The average January temperature ranges from –5°C (23°F) at Seoul to –2°C (28°F) at Pusan and 4°C (39°F) on Cheju Island. In the hottest part of the summer, however, the regional variation in temperature is not nearly so marked, with average temperatures ranging from 25°C to 27°C (77–81°F) in most lowland areas. Average rainfall is 100 to 150 cm (40 and 50 in). Nearly all the rainfall occurs in the April–September period, especially during the rainy season, late June to early August. From one to three mild typhoons normally strike the south in the early fall, with a severe one occurring every two or three years. Days free of frost number about 240 in the southern regions.

Location :
Eastern Asia, southern half of the Korean Peninsula bordering the Sea of Japan and the Yellow Sea

Geographic coordinates :
37 00 N, 127 30 E

Map references :
Asia

Area :
total: 98,480 sq km
land: 98,190 sq km
water: 290 sq km

Area - comparative :
slightly larger than Indiana

Land boundaries :
total: 238 km
border countries: North Korea 238 km

Coastline :
2,413 km