This is a British Horror Movie. I found it rather entertaining but not brilliant.
This is a story of childhood girlfriends who have grown-up and take a trip to the Appalachian Mountains for a rekindling of their friendship and thrill seeking. Lead by the character Juno they head off on an adventure into a cave system. Scary stuff happens here while their friendships and loyalties are tested.
Blood, guts, gore (red is one of my favorite colors, as long as it's not my blood

) and a lot of F-U's in this movie. Slow beginning and quick windup, but it will keep you on the edge of your seat. I enjoyed the accents and the tough girls kicking butt on the predators.
All in all... I rank this a B-- better than a C+. Enjoyable, horror.