Here's a bunch of interesting stuff:
https://en.wikipedia.org/wiki/Gwangju_Uprising is a key point in history.
https://www.youtube.com/watch?v=GHu39FEFIks is a recent politically-charged South Korean pop song. It's (intentionally paradoxically) interpreted by a young girl, but it was penned by an older, male composer. The lyrics are superficially waxing nostalgic about the Sogyeokdong district of Seoul, however during the times shown in flashbacks in the video, this used to be the location of the HQ of the Korean Defense Command, which ran a "School Greening Project" arresting and interrogating students believed to be activists in the democratization movement, and trying to turn them into informants. Several died. So when the girl sings "Do you remember Sogyeokdong? It hasn't changed at all ..." it's biting sarcasm. The music video directly features related events, including the haunting, eerie curfew sirens and government broadcasts about the SGP.
If you want to do some serious learning, this is a very good book: http://www.amazon.com/The-Park-Chung-Hee-Transformation/dp/0...
Disclaimer: I'm a German citizen living in Seoul, and I enjoy life here very much and am crazy-fond of the country and many of its people. Yet it's a very complicated place, in particular its 20th century history.
Get dozens of book recommendations delivered straight to your inbox every Thursday.