The movie THE FOREST explored this and turned the idea of the forest into a modern day ghost story.
A young woman, Sarah, has a feeling that her twin sister, Jess, has gone missing and is in serious trouble, so she decides to go to Japan to find her sister. When she arrives she finds that her sister has ventured into the suicide forest and many people warn her that anyone who goes in there and doesn't come back out soon after is most likely dead. Sarah meets a young man named Aiden who is going into the forest with a guide. Aiden claims to be a travel journalist who lives in Japan but writes for an Australian magazine.
After they wander around the first day and are about to head back, Sarah finds her sister's tent, abandoned. She is warned that they need to leave and can't stay with the tent, but she refuses to move, claiming her sister will be back that night. After waiting and sleeping for a while, strange things begin happening, and Sarah either starts having hallucinations or is actually seeing supernatural things, the audience is not sure.
The next day Sarah is frightened and maybe a little dehydrated. She's also worried for her sister, and her own safety in light of some of the things she saw the night before. Aiden, who bravely stayed near her to help protect her from the odd things in the forest, starts to worry about her. Then things just get worse. Sarah starts to have several issues, either due to the real fact that the forest is large and easy to get lost in, or due to the supernatural things that may be happening in the forest which terrify her.
In the end the sisters both come to terms with something that has been haunting them.
I can't say that this movie was terribly fabulous, but I didn't hate it. I thought the scares were obvious, but they did cause me to jump, which is unusual. The main character, Sarah, did start to really annoy me, especially after she started having a mental breakdown of sorts. There were at least two scenes in the movie where I felt the plot fell a little, plus neither of them added at all to the story. Plus there was an incident when the twins were little that was never explained, which seemed silly since it was a big plot point in the story.
As a horror movie, it was not fabulous. It wasn't really frightening, and the scares were mostly obvious. This was especially true as the movie moved on and Sarah's issues were examined more closely. The ending had a little bit of a twist, but really it was not as much of a surprise as one would have hoped. Really, the most interesting thing about this movie was the setting.
The forest is very serene and beautiful. In real life it is one of the most beautiful places someone will see. The sadness behind it, and the horror some might stumble on is real. One thing I learned from this movie, which I already knew, don't go off the path. Just don't do it. The actual forest is huge, and it is very easy to get lost. Also, there are bodies and people in there who have killed themselves or may be contemplating it. You may want to help someone, but in all honesty, you may just lose yourself.