Underrated movies: "The Descent" - claustrophobic horror

The Descent quickly became a cult classic in the world of horror, due to its thematic simplicity and claustrophobic atmosphere.
It also is the best movie the director Neil Marshall has made so far, now mostly known for having directed two action packed episodes on Game of Thrones (Blackwater and Watchers on the Wall).
The movie follows a group of women on an adventure trip into the caves of the Appalachian mountains.
Unlike modern horror movies, the interaction between the characters comes off as authentic and natural, each portraying different personalities.
The six women start their trip into the caves and quickly learn that they are threatened not only by the pitch black environment and tricky paths in the cave, but also by violent creatures living inside...the battle for survival begins.

What makes this movie special is the lack of conventions which we see in so many contemporary horror movies: No jump scares (at least not for the sake of having one), and ongoing tension.
The choice of the unique setting also proves to be a great choice, as the caves itself provide plenty of chills on their own.
The story plays out in a rather linear fashion, which is quite refreshing: Sometimes a simple plot, with no unnecessary additions works out far better than leaving the viewer with supernatural explanations which do not add up.
I do not want to spoil anything, so if you find yourself looking for a good movie to watch during the evening try out The Descent!