For me, it is not the subject matter that is incredible. It is not the topic of the photograph that is amazing. It is the skill and technique of Ansel Adams that makes this such a great photograph. The crosses are ablaze and the sky is dramatically dark, and cloudless. In Ansel Adams' words, he describes the shot:
"The gilt crosses were blazing with the glare of sunlight. The stone of the church was fairly light, but if rendered 'literally' it would have competed with the crosses. Hence I exposed to keep the stone a middle value, and the foliage is thus quite dark. The sky was a deep blue and adequately separated in value from the stone. I made a second negative at one-half the exposure, but lost qualities in the shadows and in the foliage while gaining nothing with the values of the stone and cross. (The sky was deeper, but the effect was excessively theatrical.) With both negatives, the below-normal exposure had no effect on the glare from the crosses since that was far beyond the normal exposure scale of the film."Just think about it: How many photographers nowadays with all the do-it-yourself digital brainpower, actually think about all the aspects of the scene before taking a snap-shot or photograph (and there is a big difference between the two)?
For all the searching I've done using Google and Yahoo, I can't find an example of this photograph, on the WEB to include. Nevertheless, if you go to your public library or bookstore, on page 38 of Adams' THE NEGATIVE, you'll see this photograph.
And of course, anyone can argue about "the best" B&W photograph of all time. Like I said, this is one of my all time favorites.