Cheonggyecheon Stream

Seoul once had a stream that no one heard for nearly 50 years.

It sounds absurd. A stream is meant to make a sound. Water slipping over stones babbles, water lapping at a bank patters, and in the rainy season a whole stretch of street roars with it. Yet here, there was nothing. People in Seoul went to work every morning and to the market every afternoon. They crossed right over the place where the stream lay, and the only thing they heard was car horns.

The stream is called Cheonggyecheon.

Six hundred years ago, when Seoul was the capital of the Joseon dynasty, this stream ran straight across the heart of the city. People built stone bridges over it. The most important one was called Gwangtonggyo. It joined the Gwanghwamun area to the city gate of Sungnyemun, by way of the wide street called Jongno. Many people going from one half of the capital to the other crossed that bridge.

But a stone bridge was not only for crossing. On festival days, the people of the city gathered on the bridge. They walked back and forth across its stones, laughing and talking as they went. Jongno, the street that ran past it, was the main road of the whole capital. Shops and stalls lined both sides, and people came and went from morning until night.

Then the city grew, and it grew very fast.

People poured in from everywhere. Every year there were more houses and more cars, but the roads stayed the same. At that time, Seoul needed roads more than it needed a stream. So from 1958 to 1961, the stream was paved over with concrete. The water disappeared under a flat, smooth surface for cars to drive on. Later, right on top of that lid, an elevated road was built, running straight overhead.

No one did anything wrong. People chose what was needed most at the time. That road carried goods, carried people, and carried a whole city in a hurry to move forward. But from then on, several generations of Seoul children grew up without knowing there was water under their feet.

In July 2003, the first machines climbed onto the elevated road. But this time they had not come to repair it. They had come to take it down.

Beam by beam, slab by slab, the concrete was cut apart and hauled away. After the elevated road, it was the turn of the concrete lid. And when the last piece was lifted, sunlight fell into the streambed again. It had not reached the water for more than 40 years.

The work took 27 months. By October 2005, water was flowing again through the middle of Seoul, along a stretch of nearly six kilometers.

There is an honest detail here that few people mention. The stream was given back its old place, but not enough water came back on its own. So every day, the city pumps about 120,000 tons of water into the streambed. It comes from the Han River and from groundwater collected in subway stations. So the water flowing there today is water that has to be tended. Every day, the pumps have to run to keep it flowing.

The surprise is this: give it water, and a great deal of life finds its own way back.

In 2003, just as the work site opened, people counted four kinds of fish in this stretch of the stream. Five years later, a new count found 25 kinds. Birds went from six species to 36. Insects went from 15 species to 192. The plants along the banks went from 62 species to 308. Counting the other groups too, this place went from 98 species to 626, in only five years.

No one hung birds in the sky. The birds came by themselves, following the water.

Then summer came, and the people of Seoul noticed something else. Along the stream, it was clearly cooler than out in the streets. Measurements showed a difference of 3.3 to 5.9 degrees Celsius, compared with a big road running parallel a few blocks away. The same city, the same noon, and only a short walk apart.

Today, stairs lead down from the sidewalk to the stream. It is only a short staircase, yet it feels like walking into another level of the city. The noise of traffic stays up overhead, growing fainter and fainter, and in its place comes the sound of water.

The streambed is not very wide, and both banks are lined with stone. In some stretches, flat stones are set in a row across the water, as a path to the other bank. Children love that spot most. They hop from one stone to the next, with water slipping through the gaps right under their feet. Adults often sit down on the bank, dangle their legs in the water and tip their heads back to look up. Above them, 22 bridges cross the stream, and higher still rise the glass towers of Seoul.

At the head of the stream, by Cheonggye Plaza, the water drops down a two-tiered waterfall, four meters high. Right beside the falls is a special stone bank. It is built from stones brought from eight provinces across South Korea. Each stone has its own color and its own grain, as if every region had given one stone to start the stream on its way.

The old stone bridge, 600 years old, is still there too. Gwangtonggyo went out of use in 1958, the very year the stream began to be covered. When the stream was restored, the city had the old bridge dug out and measured part by part. Then it was set up again in 2005. People walking there today still cross that bridge, close to the place where the people of the old capital once crossed it on festival days.

On a summer noon in the middle of Seoul, a flight of steps leads down below the street. Anyone who walks to the bottom step and stands still for a moment will hear the water.

The sound flowing right under your feet is the sound a whole city could not hear for nearly 50 years.