I have to come up with a 2 week summer camp curriculum for a ESL class. Each day will consists of a 4 hr. period. I would appreciate if you could give me an idea of what I should teach for each day for 4 hr. during this 2 week shedule. This is all indoor class activities only.

hmm.. Many Korean highschool students are not good at english at all. Korean highschools teach grammar or reading, but their listening and speaking is horrible..
Some students might be able to talk with you, but hmmm...

I would bring some age-appropriate materials to give them a sense of how our language mixes with our culture.

Something like a menu from McDonald's or KFC would be ideal as they are most likely well aware of may items on the menu in their own language.

You could also introduce them to some American summer camp ideas like different camp foods, games and classic sing-along songs.

The key is to engage them as directly as possible and encourage them to interact utilizing the language as much as possible.

In terms of "what" you should teach, I think it is prudent to see where they are coming form. Many of them may already have a basic understanding of English. Context may be the issue there. If they are staring with NO vocabulary, start with the conversational basics.