Perhaps the stream above is Cheonggyecheon, but it's worth remembering that there were dozens of streams in Seoul that were covered up in the twentieth century by both Japanese and Korean governments.Choi In-kyu, the director, went on to direct several other (less 'pro-Japanese') films before being kidnapped off to North Korea during the Korean War, including 'Hurrah for Freedom' (1946), the first DVD put out by the Korean Film Archive. It includes a scene in which the main character, an independence fighter, has rescued his friend from a Japanese police officer (I guess we're assuming he wasn't Korean) by stabbing the officer, and flees over (and then under) a bridge crossing Cheonggyecheon. I'm quite certain this is the same bridge (Gwanggyo) seen in the post at the Marmot's Hole, which is now the second bridge to be seen along the restored stream when walking from its source. Thanks to panorama software and a screenshots of a pan across the bridge, we can see almost the full length of the bridge.
Here's a shot of what it looked like underneath:
What really prompted me to post these was a comment by Sperwer at the Marmot's Hole mentioning the fact that Obaltan, (The Aimless Bullet), a 1961 film by Yu Hyeon-mok considered a classic today, features a scene in which one of the main characters flees the police after a robbery by running through Cheonggyecheon - under the then ongoing construction which was covering the stream:
(Due to it being a panorama made from screenshots taken from a pan, both people seen above are the same person)
Very cool. I watched the film when the dvd came out back in 2002, but did not know anything about Cheonggyecheon at the time (it was later that year that it became mentioned more often in the English language press), so it was fascinating to watch it again, knowing where this scene took place.