Stuff to Blow Your Mind is all about the journey to the edge of human understanding, and there are a number of paths to that terrifyingly awesome precipice. We can get there through science, science-fiction, music, visual art, mythology, meditation and psychotropic substances.
But we can also get there through horror. As a horror fan and your humble Stuff to Blow Your Mind co-host, I particularly love it when a work of horror delivers me into the unknown or unknowable. So here are 21 psychedelic horror films permanently burned into my mind.