South Korea Map

The southern half of a peninsula

South Korea, officially the Republic of Korea, occupies the southern part of the Korean Peninsula. Its only land border is the Demilitarized Zone (DMZ), a strip about 250 kilometers long and 4 kilometers wide drawn along the 1953 armistice line with North Korea. Because that border is closed, the country works in practice like an island, reached by sea and air. The Yellow Sea lies to the west, the East Sea (Sea of Japan) to the east and the Korea Strait to the south, and more than 3,000 islands are scattered mostly off the ragged southwest coast. The country covers about 100,400 square kilometers and has about 51.7 million people (UN World Population Prospects, 2025 estimate), roughly half of whom live in the Seoul Capital Area of Seoul, Incheon and Gyeonggi Province. Its total fertility rate of 0.75 in 2024 was among the lowest ever recorded anywhere.

Mountains, rivers and Jeju

About 70 percent of the land is hilly or mountainous. The Taebaek Mountains form a spine close to the east coast, which is why the eastern shore is steep and straight while most rivers drain west and south. Seoraksan (1,708 meters) in the Taebaek range and Jirisan (1,915 meters), the highest peak on the mainland, are the best-known national parks. The highest point in the country is Hallasan (1,947 meters), the shield volcano that forms Jeju Island, 80 kilometers off the south coast. The Han River flows through Seoul to the Yellow Sea, and the Nakdong, the longest river entirely in South Korea, reaches the sea at Busan. The broad tidal flats of the west and south coasts were listed by UNESCO as the Getbol World Heritage Site in 2021.

Seasons: when to go

Winters are cold and dry, driven by Siberian air, and Seoul's January average sits below freezing. The summer monsoon, jangma, usually runs from late June to late July and brings a large share of the year's rain, and typhoons strike mainly the south coast and Jeju in August and September. Spring (April, with cherry blossoms) and autumn (October, with mountain foliage) are the most comfortable times to visit.

Provinces and Major Cities

South Korea has 17 first-level divisions: Seoul Special City, Sejong Special Self-Governing City, six metropolitan cities, six provinces and three special self-governing provinces (Jeju, Gangwon since 2023 and Jeonbuk since 2024). City populations below are 2025 resident-registration figures, rounded:

• Seoul - About 9.3 million (about 26 million in the Capital Area), capital since the Joseon dynasty chose it in 1394, with Gyeongbokgung Palace and the Han River at its center
• Busan - About 3.3 million, the largest port and southern gateway, with ferries to Fukuoka; it hosted the UNESCO World Heritage Committee in July 2026
• Incheon - About 3.0 million, home of Incheon International Airport on Yeongjong Island and site of the 1950 Incheon landing
• Daegu - About 2.4 million, a textile center where Samsung began as a trading company in 1938
• Daejeon - About 1.4 million, home to the Daedeok research district and KAIST, at the junction of the main rail lines
• Gwangju - About 1.4 million, the main city of the southwest, remembered for the May 1980 pro-democracy uprising
• Ulsan - About 1.1 million, the base of Hyundai's main car plant and shipyards
• Sejong - About 400,000, a planned administrative city where most central government ministries have moved since 2012

The KTX high-speed line, opened in 2004, links Seoul and Busan in about two and a half hours.

From division to democracy

Korea was a Japanese colony from 1910 to 1945. At liberation the peninsula was split at the 38th parallel into Soviet and American zones, and the Republic of Korea was founded in the south in August 1948. The Korean War of 1950-1953 ended with an armistice, not a peace treaty, and the front line became today's border. Decades of authoritarian rule under Park Chung-hee and Chun Doo-hwan coincided with rapid industrial growth, the "Miracle on the Han River", which took South Korea from one of the world's poorest countries in the early 1960s to a high-income economy. Mass protests won direct presidential elections in 1987. In December 2024 President Yoon Suk Yeol briefly declared martial law; he was impeached and removed by the Constitutional Court in April 2025, and Lee Jae-myung won the election that June.

Interesting Facts

• The Korean alphabet, Hangul, was created under King Sejong in 1443 and promulgated in 1446; 9 October is Hangul Day
• Samsung and SK Hynix together make most of the world's DRAM memory chips
• More than half of South Koreans report no religion; Protestants, Buddhists and Catholics are the largest faith groups
• Seventy years with almost no human activity have made the DMZ a refuge for wildlife, including wintering red-crowned cranes