Cathedral in the Desert:

 Escalante Arm of Lake Powell at the end of Clear Creek

The waterway ends in a passage that is completely overhung by deep massive alcoves.   At waters end there is a ledge up that supports and active stream.  Following this stream reveals more overhung alcoves as the stream bends through the deep canyon, ending in a pour-off containing a rope.   Too slippery and steep to proceed we returned to the boat by the same way that we came.