The Korean Peninsula stretches southward from the northeastern part of the Asian continent between 33 and 43 North Latitude and 124 and 132 degrees East Longitude. The peninsula's standard meridian is 135, which is nine hours ahead of GMT.
Bordered by the Amnok and Tumen Rivers to the north, which also serve as borders with China and Russia, and facing Japan across the East Sea, the peninsula has been divided at 38 North Latitude into the capitalist Republic of Korea (ROK), or South Korea, and the communist Democratic People's Republic of Korea, commonly known as North Korea, since 1945, as a result of the Cold War.

The total area of the peninsula is 222,196 km², comparable in size to that of the U.K., New Zealand, or Romania. South Korea occupies 99,434 km², or 45% of the total landmass, while North Korea covers 122,762 km², the remaining 55%.
Approximately 70% of the land is mountainous, mainly in the north and east, with mountains gradually descending towards broad coastal plains along the southern and western coasts. Most rivers have their tributaries on the north and east sides, flowing into the Yellow and South Seas. Off the southern coast lie over 3,200 islands of various sizes, offering breathtaking scenery.
The eastern coast runs along steep mountain slopes, while the western and southern coasts have curved shapes and wide alluvial plains in some areas. This asymmetrical topography is believed to have been caused by tilting movements, subsidence in the western coast, and upheaval in the eastern coast, resulting in the ridge line of the watershed running on the eastern side.
In general, rivers flowing into the eastern coast are short with steep gradients, while those like the Han River, the Keum River, the Nakdong River, and the Seomjin River, flowing into the Yellow and South Seas, are long with gentle gradients.

Koreans, descendants of Mongolian Tungus stock, form a homogeneous ethnic group with their own language, culture, and customs, distinguishing them from neighboring Japanese and Chinese. Known for their generosity, warmth, and industriousness, Koreans are recognized as one of the hardest working people globally.
As of 2024, Korea's population was estimated at about 51 million, with a population density of 514 persons/km², ranking among the highest globally alongside Bangladesh, the Netherlands, and Belgium. With a total land area of 99,601 km², farmland covers 20,263 km² (20%), while forested areas span 64,948 km² (65%). Only 4% of the land is used for housing, public, and industrial purposes.
The Han River Basin, covering 26,018 km² (26% of the national land area), accommodates approximately 21 million people. The Nakdong River Basin, spanning 23,817 km², accommodates about 12 million people.
Of the total land area in Korea, approximately 20.8% (20,676 km²) is suitable for cultivation, with the remainder being hilly or mountainous. Only about 5% of the area is used for building sites, roads, and factories.

Korea falls within the moderately humid zone of medium latitude, characterized by distinct seasonal climates influenced by dry, cold continental air masses in winter and humid, warm air masses from the ocean in summer. The temperature fluctuates widely between seasons, with considerable regional diversity.
Precipitation distribution is more varied than temperature, with about 70% of the annual precipitation of 1,283mm occurring during the rainy season from June to September. Approximately 18% of the total annual precipitation falls during the dry season from October to March. Korea is affected by two or three of the approximately 28 typhoons occurring in the northwestern Pacific Ocean each year.
The climate is conducive to conifer and deciduous forests, although unequal rainfall distribution has limited dense vegetation. Forests are well-preserved and managed in mountainous areas, particularly since the 1960s.

The Han River, with a basin area of 26,018 km² and an annual runoff volume of 27.7 billion m³, is the largest river in Korea. On the other hand, the 552 km Nakdong River is the longest.

Key characteristics of rivers in Korea include relatively short river reaches and steep channel slopes, leading to rapid floods with enormous peak discharges compared to other continental rivers. Flow variations are high, with coefficients of river regime ranging from 100 to 700, posing challenges for flood control and water management.