Seoul’s great leap into the modern world began in the 1960s. Shaking off the trauma of the Korean War and riding roughshod over centuries of tradition, the city rapidly transformed the downtown area with highways and high-rises. The planners showed little regard for history or nature. Old districts were leveled, and streams were concreted over.

Cheonggyecheon, a stream that had flowed through the city since its founding, was filled in and an elevated highway built over its former course. Gone but not forgotten.

When the highway was demolished in 2003, the city initiated an ambitious plan to restore the stream. The scheme was controversially expensive (with a final bill of $281 million), but in the 10 years after its opening in 2005, it has become an area beloved by Seoulites — a seven-mile-long sunken waterway fringed by picturesque paths and interspersed with public art.

In its new incarnation, Cheonggyecheon is more than a stream. It is the very heart of Seoul.