It's very hard to describe this little film gem by Italian director Dario Argento (he also wrote the screenplay). The premise is a newcomer to an elite ballet academy gradually comes to realize that the staff of the school are actually a coven of witches bent on chaos and destruction. This is actual the first in a trio of movies that the director refers to as "The Three Mothers" that deal with the witches. The other two films are Inferno and Mother of Tears.
Suspiria combines one of the gretest "jump out of your seat" moments in horror film history. I wont spoil it. Typcial of many Argento movies is the Italian giallo style of storytelling with a deep mystery and a crime. This goes beyond that though with it's surrealistic set pieces and dream-like state. And there's plenty of gore too.
A truly unique film that remains one of my favorites.