Absolutely loved it!
Family heads off into the back of nowhere in the US, camping out under the stars. The youngest member of the family is a young autistic lad who has to keep filming everything and thereby provides the ability to record what's happening. The family lose their way on one of the backroads and come across a very eerie discovery...
You get about 5 mins at the start of the movie to settle down and then the tension kicks in with gusto and you're just kept on the edge of your seat right up the the final scene in the movie! The team who made are just absolutely brilliant at finding new ways of keeping the tension going, careful use of lighting ( or lack of it! ) in key places just keeps you right on edge.
Probably one of the best films I've seen in a long while. No silly effects, nothing is overdone and no unnecessary CGI, just good a good old scare-a-minute alien monster flick done in the Blair Witch style of story telling.