Seoul

South Korea

A folklorist named Im Kwon-taek once collected a story from the Gugi-dong neighborhood in what is now Seoul. Elders spoke of a large serpent, the Imugi, that lived in a pond on Namsan Mountain, waiting to become a dragon. The serpent was said to vanish underground into a cave and reappear miles away at a spring near the main gate of Gyeongbokgung Palace. The story is not just a myth; it maps the hidden water table that has always determined life in this valley.

Seoul occupies a basin defined by the Han River to the south and a tight ring of mountains—Bukhansan, Dobongsan, Gwanaksan, and the ridges of Namsan—that rise sharply to an average of 500 meters. The mountains are granite and gneiss, worn into steep, forested slopes that direct every drop of rainwater into the Han or into underground aquifers. This geography created a natural fortress, a fertile floodplain for rice, and a constant, critical challenge: controlling water within a defined, defensible bowl. The human history of Seoul is a 2,000-year project of walling, channeling, honoring, and ultimately mastering these hydrological facts.

The earliest significant settlement was Wiryeseong, the capital of the Baekje Kingdom beginning in 18 BCE. Baekje’s founders chose a site within this same basin, just south of the modern city center near present-day Seongnam. They built their fortress, Pungnap-dong, on a bend of the Han River, using the water as a moat and a transportation route. When the kingdom of Goryeo unified the peninsula in 918, its capital was at Kaesong, but it maintained a secondary palace in Seoul, then called Namgyeong, recognizing the strategic value of the Han River valley for trade and communication. The definitive commitment to this landscape came in 1394, when King Taejo, founder of the Joseon Dynasty, selected Hanyang as his new capital after geomantic advisers pronounced it an ideal site.

The geomantic practice of pungsu (Korean feng shui) interpreted the land’s forms as channels of cosmic energy. The mountains to the north were the “main mountain,” Baegaksan (now Bukhansan), representing stability and protection. South Mountain, Namsan, served as the “front mountain,” guarding the approach. The Han River was the “water of the south,” a vital life-giving force that had to flow correctly to ensure prosperity. The palace, Gyeongbokgung, was positioned precisely at the foot of Baegaksan, with its main gate, Gwanghwamun, facing south toward Namsan and the river. An east-west axis of secondary palaces, Changdeokgung and Changgyeonggung, completed the layout. The entire city was encircled by the Seoul City Wall, an 18.6-kilometer stone barrier that traced the mountain ridges, its gates placed according to pungsu principles at the cardinal directions. The land proposed a fortified, energy-rich bowl; the Joseon court responded with a capital whose very streets were an act of landscape cosmology.

For five centuries, the city’s life was constrained by its walls and its water. Population, which fluctuated between 100,000 and 200,000, was limited by the ability to feed people within the basin and bring grain via the Han. The city’s aristocracy lived in hanok houses built with their backs to the northern slopes for warmth, their layouts adhering to Confucian hierarchies and seasonal sun angles. Commoners crowded in the lower valleys, where seasonal floods were a recurring hazard. The Cheonggyecheon stream, which ran east-west through the city center, was both an open sewer and a vital drainage channel, its floods routinely washing away the precarious dwellings of the poor. The relationship was elemental: the mountains provided defense and spiritual assurance; the river and streams provided sustenance and periodic catastrophe.

This equilibrium was shattered in the 20th century by technologies that overrode the basin’s natural limits. The Japanese colonial occupation (1910-1945) began the process, demolishing sections of the city wall and building a modern grid over the old organic layout, but it was the Korean War (1950-1953) that leveled the city. The post-war reconstruction and the ensuing “Miracle on the Han River” represented a total renegotiation with the landscape. The mountains, once sacred and defensive, became real estate obstacles. They were carved into terraces for apartment blocks, their lower slopes blanketed in banjiha—semi-basement dwellings—for a rapidly urbanizing population. The Han River, once a natural border and spiritual artery, was straightened, diked, and lined with massive concrete floodwalls. Eleven bridges were built across it in two decades, stitching together a metropolitan area that exploded from 2.5 million in 1960 to over 10 million by 1990. The city burst through its mountain ring, consuming the surrounding Gyeonggi Province plains.

The Cheonggyecheon stream became the symbol of this new, engineered relationship. By the 1960s, it was a polluted, open-channel drain, and the government covered it with a elevated highway, burying the water entirely. For decades, the highway carried traffic over the forgotten stream. Then, in 2003, Mayor Lee Myung-bak initiated a project to demolish the highway and restore 5.8 kilometers of the stream as a public greenway. The restored Cheonggyecheon is not a natural creek; it is a carefully engineered water feature, with 40% of its flow provided by pumped-in, treated water from the Han River. It is a simulacrum of nature, a testament to the city’s desire to remember the hydrological logic it spent the 20th century conquering. The project cooled the local microclimate, lowered urban temperatures, and became a linear park, but it also displaced thousands of market vendors, revealing the ongoing tension between ecological gesture and social cost.

Today, the conversation continues in the language of data and infrastructure. Seoul’s subway system, one of the world’s longest and busiest, follows the paths of old valleys and under riverbeds, a subterranean mimicry of the surface watershed. The city’s notorious air pollution, trapped by the mountain ring’s inversion effect, has led to a network of 27 official “wind paths”—corridors where building heights are restricted to theoretically channel cleaner air from the surrounding mountains down into the basin. Even the myth of the Imugi serpent finds a modern counterpart in the city’s vast, computerized water management system, which monitors reservoir levels in the mountains and controls the release from the Palace-tang weir on the Han to prevent flooding. The mountains are now national parks, crowded with hikers on weekends, a recreational pressure valve for one of the world’s densest urban populations.

In the Jongno district, beside the restored Cheonggyecheon, a section of the original city wall has been excavated. The stones, fitted together without mortar, follow a seam in the granite bedrock. Just meters away, the glass curtain walls of corporate headquarters reflect the same ridge line. The two structures—one designed to keep people out, the other to project global economic power—are both direct, pragmatic responses to the same immutable fact: a ring of mountains, a flowing river, and a bowl of land that has demanded, for over two millennia, a specific and relentless kind of attention.