Hiking in the Southwest USA is always an adventure.  On one hiking trip with my son David our guide (who was part Indian) noticed that we were experienced hikers so he took us up to a remote mountain.  We saw rock faces that were thousands of years old.  One surface was exposed to the elements and the winds had carved a 3D etching into the wall.  The surface was brittle and thin; able to break if you touched it.  It was a remarkable sculpture created by nature.  
 
20” x 30” metal print.  Ready to hang.