At this place are a bunch of those really amazing rock formations.
It has something to do with "harder" rocks falling down onto softer ones. Wind and rain destroys the softer stone but leave a small stem - as the harder rock on top acts like an "umbrella".
At least that's what I remember! *LOL*
Or as wikipedia would say:
"Hoodoos are composed of soft sedimentary rock and are topped by a piece of harder, less easily-eroded stone that protects the column from the elements."