when Geologists can't explain things,
rather then admit there education may be lacking. or admit
it may have been carved too far back to fit the status quo
they just say natural erosion.
actually many things could have done it, including lightening I guess,
or testing a death ray, invented millions of years ago before they wiped out
the Dinosaurs & themselves
(sorry just making the point nobody really knows what happened on earth from day 1 )
but natural or not, if the sun shines though it and causes a beam of light,
on a certain time of day or year, you can also be certain
some person or group noticed it.
and what they did where the beam hits is anybody's guess