This was a movie, probably from the early 2000s. A horror movie where a bunch of teens go on vacation in Mexico, or a Spanish speaking country. They see a weird lady there (I think she may have been by a waterfall, and she may have drowned her children). That night the teens retreat to the house/cabin they are staying in. Then weird things start to happen and the teens are being hunted by something from inside the house and it starts killing them off one by one. When they open the cabin door to try and run away, the outside world is gone, it's just a black void. If something goes out, it never comes back. That's all I can remember but I really want to watch it again