Cheonggye Stream

Visitors walk under umbrellas on display over Cheonggye stream during a campaign to raise donations to help underprivileged children in Seoul, South Korea, Tuesday, Sept. 29, 2015. (AP Photo/Ahn Young-joon)

Ahn Young-Joon/AP

Visitors walk under umbrellas on display over Cheonggye stream in Seoul, during a campaign to raise donations to help underprivileged children.

Kindergartners drink waters near a poster to mark the World Water Day, which falls on March 22, on Cheonggye Stream in Seoul, South Korea, Thursday, March 20, 2014.

Ahn Young-joon/AP

Kindergartners drink waters near a poster to mark the World Water Day, which falls on March 22, on Cheonggye Stream in Seoul, South Korea.