Spoilers! WHY?????
Why did the villagers keep this a secret? "A curse, from long ago" (or whatever they said)--why don't they go to the police or some kind of authority or just plain MOVE away from the area? What's in it for them to keep the secret? What do they get out of it? They obviously know what will happen if someone goes into the fog, and they obviously don't want anyone to go into the fog (the guy with the expensive blonde highlights yells at them all scary-like to leave but gives them no explanation why--how about "hey, weird sh*t happens in the fog, stay away!"), so why do they just leave the strangers alone to stumble their way in if they don't want anyone to go in there?
What was the purpose of the fog? To lure outsiders to their doom? So the villagers are cursed, and the curse dictates that they kill anyone that goes into the fog because they'll become possessed...and they don't want anyone to go into the fog...so why not fence in the fog (as others have said) or put a scary guy there with one of those big ole machetes that yells "stay the *beep* away from the fog" in what I have read is some pretty silly Polish dialog?
And if secrecy about the "shrine" is such a BFD, why do they let Marcus go in the end? What is to prevent him from telling the entire flipping world?
Yes, I know it's a horror movie and we're supposed to suspend our belief, but there was too much that was left without explanation. If you're going to bitch at me about this, save your breath. I can and will accept (and love) supernatural elements in a film if they are willing to make it seem plausible (ala The Exorcist), but this left too many unanswered questions.
This movie is perfect for a "100 Things I Learned" thread.