Cheongsong County, North Gyeongsang Province (South Korea)

Here is gif image.
https://www.youtube.com/watch?v=YucLx--71TE
http://www.saynews.co/sub_read.html?uid=36180§ion=sc3§ion2
Tomislav Šipek, 23 December 2019

From the Cheongsong County website:

The county flag

• The top part in green symbolizes "green mountains" in Cheongsong-gun.
• The lower left part in blue symbolizes "clean rivers" and the lower right part in yellow symbolizes "rich fields." The entire symbol represents the image of an energetic rural area that pursues future-oriented progress.

researched by Phil Nelson, 12 October 2005