Why is South Korea's land full of mountains but without natural lakes

When discussing the natural beauty of a country, we often combine two elements: towering mountains and tranquil waters. However, South Korea presents a stunning geographical paradox—despite covering an area of over 100,000 square kilometers, the country has no natural lakes larger than one square kilometer. This phenomenon is like searching for a needle in a haystack and is vastly contrary to our intuition about how a developing country should look.

This statement seems almost impossible. Compare it to neighboring countries like Japan, which, although also mountainous, still have large natural lakes such as Lake Biwa. Or look at how our country has vast lakes like Poyang Lake and Dongting Lake. South Korea’s unique reality is not just a coincidence but the result of a very specific geographical structure.

Extreme Topography: When Two-Thirds of the Land Are Mountains

The key to understanding the absence of natural lakes in South Korea lies in its land architecture. Two-thirds of the entire area of South Korea consists of steep, rugged mountains. This is not just a statistic but a geographical reality that defines every aspect of life on the peninsula.

The Taebaek and Sobaek mountain ranges stand like the backbone of a giant dragon, dividing the region into small, separated parts. Such steep and fragmented terrain creates conditions highly unfavorable for lake formation. If you stand atop a South Korean mountain and look around, what you see are continuous mountain ranges receding into the distance, not expansive plains like those found in Jiangnan or central Yangtze regions.

This contrast with South Korea’s limited land area becomes even clearer when compared to China. The vast Chinese plains with open terrain allow rivers to flow slowly, and small basins can hold large amounts of water. Conversely, South Korea—despite its substantial size—is enclosed within a network of mountains that leaves no room for natural basins to form.

Hydrological Dynamics: Water That Rushes Straight to the Sea

South Korea’s geographical structure creates a fundamentally different hydrological system from most other countries. When it rains, water does not collect in basins to form lakes. Instead, it flows rapidly down steep mountain slopes through narrow valleys, directly rushing toward the sea.

The Taebaek Mountains, especially on the eastern side with their steep inclines, serve as the main barrier. In the eastern regions of South Korea, mountain cliffs plunge directly into the ocean without leaving gaps for lakes to form. As a result, although the eastern scenery of South Korea is indeed beautiful, you will not find calm waters—only turbulent seas.

Traveling west offers slightly better prospects, but disappointment remains. Although the terrain becomes flatter toward the west, branch mountains such as Cheolma and Ruling continue to carve the land into narrow gorges. Such topography is ideal for terraced farming but completely unsuitable for creating large water bodies.

Even in the southern parts of South Korea, where the Taebaek Mountains begin to descend into lower hills, conditions do not improve. These gentle terrains are even more problematic—water flows lack deep basins to form lakes. This is the geographical irony: without mountains creating basins, water cannot be stored.

Human Solutions: Artificial Reservoirs Replacing Natural Lakes

The absence of large natural lakes in South Korea forces residents to seek creative solutions. The lakes seen on maps—such as Seojang Lake and Daqing Lake—are actually man-made constructions. These names that sound luxurious are the result of dam constructions that hold back river flows.

Water infrastructure has become an obsession in South Korea due to urgent needs. If these dams were to be removed, the locations would revert to barren riverbeds. The logic of development in South Korea is simple but harsh: whenever a river is suitable, a dam is built downstream. There is no alternative because they need water for irrigation, power generation, and drinking supplies.

Reliance on artificial reservoirs has consequences. South Korea’s water system essentially flows only “straight,” without natural buffers. As a result, during dry seasons, rivers dry up, while during heavy rains, floods can easily occur. Compare this to China’s water system, which has large lakes around the Yangtze River capable of absorbing and storing floodwaters.

Economic Limitations: Restricted River Transportation Networks

The lack of natural lakes and limited water systems also constrain economic development. China’s Yangtze, Huai River, and interconnected lakes enable cargo ships carrying thousands of tons to reach inland areas. This infrastructure reduces transportation costs.

In contrast, most rivers in South Korea are only suitable for recreation and aesthetic purposes. Larger ships cannot navigate many regions. The immediate consequence is that river logistics costs cannot be kept as low as in countries with more developed water systems. South Korea relies more heavily on land transportation routes, which are more expensive and complex.

Culture and Urban Development: Terraced Architecture as Identity

South Korea’s unique geographical structure has shaped its culture and development patterns. Because flat land is very limited and mountains dominate, developers are forced to build upward along slopes. This is why many South Korean cities feature layered buildings climbing the contours of hills, creating a dense urban panorama.

This contrasts sharply with Chinese cities, which often develop around lakes or along major rivers, resulting in sprawling horizontal layouts. South Korean cities, on the other hand, grow along valleys or coastlines, with architecture that is highly vertical. The high population density within limited space is a defining characteristic of South Korean urban areas.

Strategic Implications: Geography as a Defense Barrier

From a military perspective, South Korea’s mountainous geography has profound strategic implications. Fully mountainous terrain is easy to defend but very difficult to deploy large mechanized forces across. This partly explains why the Korean War was prolonged.

Tanks require flat terrain for rapid movement—something rare in South Korea’s predominantly mountainous landscape. Modern artillery is also difficult to move through rugged terrain. Ultimately, battles rely on infantry fighting over mountain peaks, a costly operation in terms of human lives and resources.

Furthermore, the absence of large bodies of water—due to the lack of natural lakes—weakens naval advantages. Control of the sea cannot easily translate into land dominance, and amphibious operations become very difficult. Geography thus becomes one of the hidden factors behind the long duration of conflicts.

Conclusion: South Korea’s Paradoxical Extent

In the end, South Korea is a fascinating geographical paradox—a country with a relatively large land area but extremely limited flat space and no large natural lakes. Two-thirds of the land is mountainous, no lakes larger than one square kilometer, and the hydrological system is hurried and direct—these are the characteristics that define South Korea’s physical structure.

These geographical limitations have determined everything: how residents build their cities, how they develop their economy, how they wage war, and even how their culture evolves. The fact that South Korea’s territory is filled with mountains and devoid of natural lakes is not merely a shortcoming but a reality that has shaped the nation’s unique identity. It reminds us that geography is not just a backdrop of history—geography is the writer of destiny.