Unearthing Buried Waterways

"SEOUL, South Korea — For half a century, a dark tunnel of crumbling concrete encased more than three miles of a placid stream bisecting this bustling city...

Today, after a $384 million recovery project, the stream, called Cheonggyecheon, is liberated from its dank sheath and burbles between reedy banks. Picnickers cool their bare feet in its filtered water, and carp swim in its tranquil pools.

The restoration of the Cheonggyecheon is part of an expanding environmental effort in cities around the world to 'daylight' rivers and streams by peeling back pavement that was built to bolster commerce and serve automobile traffic decades ago."