South Korea

South Korea is a country in.

History
Homer once complained about the quality of Korean animation.

Marge once took the kids to Korea Town after they became "foodies".

While trying to be cool like his new neighbors, Homer took Bart and Lisa to a Korean gang film festival.

The Simpson family and The Evergreen Terrors visited Seoul, South Korea for a Conflict of Enemies which Bart was part of.

Non-canon
Kim Jong-il was once seen talking to a man who resembles Smithers about a treaty that would reunite North Korea and South Korea. He then got an email from South Korea which read "you stink". At that point he told the other man to tear up the treaty, stating that "Now there shall never be peace! Never!" The email however, was actually sent by the Bart virus, which was causing trouble all around the world.

Behind the Laughter

 * The Simpsons is animated in South Korea.