Howard’s Mill
No, it’s not a documentary. It’s fiction.
With that out of the way, it’s a neat little film which takes a few pages out of the Blair Witch playbook. It plays the story fairly straight, does some supernatural shenanigans in the back half of the movie – which are clearly telegraphed in the first half so there’s no real shock – and has one of the most ludicrous post credits scenes I’ve seen in a while.