As a young employee at Hyundai Construction in the 1960s, Lee Myung-bak helped pave over the Cheonggyecheon stream in central Seoul. Four decades later, as mayor, he tore the pavement out. Both acts made him famous. The second one made him president.

The stream had reasons to be buried. By the mid-1950s, Cheonggyecheon was an open sewer running through the center of a city trying to rebuild after colonization and war, a symbol of the poverty and filth the country was desperate to leave behind. The government covered it with concrete starting in 1958, and by 1976 a 5.6-kilometer elevated highway carried 168,000 vehicles a day over the spot where water once ran. Residents who'd been living along the banks were displaced to remote parts of the city. In their place, over the following decades, something else grew. The highway district became a dense commercial zone of more than 60,000 shops and hundreds of thousands of workers. Beneath the highway's shadow, a sprawling flea market of street vendors built livelihoods in the cracks of the infrastructure.

The highway had reasons to come down. By 2001, safety inspections revealed cracked slabs, corroded steel, insufficient load-bearing capacity. Keeping it standing would cost 100 billion won and three years of repairs. Residents and workers near the highway suffered respiratory disease at twice the rate of other Seoul neighborhoods. Benzene levels exceeded city standards. Lee, running for mayor in 2002, promised to tear the highway down and daylight the stream beneath it. Seventy-nine percent of Seoul residents supported the idea. He won. Demolition began July 1, 2003. The restored stream opened October 1, 2005.

The world loved it. Ten million visitors in the first three months. Biodiversity along the corridor increased 639 percent, according to Seoul Metropolitan Government monitoring data. Temperatures along the stream dropped 3.3 to 5.9°C compared to parallel roads. Property values within 50 meters rose 30 to 50 percent. TIME named Lee a "Hero of the Environment" in 2007. Two months later he won the presidency in a landslide.

So much for the brochure.

A survey of 3,265 merchants in the project area found that 95.75 percent opposed the restoration. The city held approximately 4,200 meetings with affected businesses. Its official principle, stated plainly in the Seoul Metropolitan Government's own records, was "no direct compensation" for business interruption or relocation. The merchants got meetings. They did not get money.

The street vendors got worse. Their activity was technically illegal, which meant they were entitled to nothing. Lee suggested they relocate to the grounds of Dongdaemun Stadium. The vendors opposed the move. On a cold Sunday in November 2003, a demolition company hired by the Seoul Metropolitan Government paid hundreds of homeless people 60,000 won each, about $44, to attack the remaining vendors and drive them from their stalls. The city later explained to a local newspaper that due to tight demolition deadlines, recruiting people off the streets near Seoul Station was "inevitable." Riot police drove out the last holdouts.

No individual vendor's name survives in the accessible English-language record. Their livelihoods were technically illegal, which made them technically invisible, which made their displacement technically nothing that required documentation.

The vendors who accepted relocation to Dongdaemun Stadium discovered the promise was temporary. The stadium itself was demolished in a subsequent "urban regeneration" project. The relocation site got erased too.

By 2011, 98 percent of land use changes along the reconstruction districts had converted to hotels, commercial offices, and educational institutes. Academic researchers found that relocated businesses experienced "severe hardships and distress." The urban poor had been pushed away from central sources of income and from civic life itself.

The stream, meanwhile, is not quite what it appears. Water doesn't naturally flow through the Cheonggyecheon for most of the year. The city pumps over 120,000 tons daily from the Han River to keep it running. The streambed is concrete. As researcher Eunseon Park of Yonsei University observed, it is:

The restoration restored an idea of a stream.

The highway was ugly and dangerous and collapsing. The health data was real. The political mandate was overwhelming. Lee Myung-bak faced a genuine infrastructure crisis and chose a solution that transformed his city. And the vendors who'd scraped together livings in the highway's shadow got paid $44 to be attacked and then lost even the place they were told to go. The stream got restored. Whose city disappeared to make room for it, the brochure never says.