A fantastic Korean (south) tale about a "haunted" forest, people who have lived there, and a couple other things. Very intricate and convoluted plot-wise, it all comes together into a very interesting story. There's a bit of creepy-ness due to the spiders, and the forest. There's some murderous rampage, but it's fairly tastefully done.
You can take this as a murder mystery, or a psychological thriller, or a Korean myth/fable. It works well as all, I found it highly enjoyable.
If you're not good at recognizing Asian faces, keeping track of who's who can be difficult. Keep an eye on the costumes each person is wearing, sometimes that's the only way to keep track of who is who. The costuming department did a fairly good job there, and that would be enough if it weren't for the fact that the movie spans a large chunk of time and you can't really wear the same thing day in, day out.