Cathedral Rock is called the most photographed object in the state of Arizona, and it's not hard to see why. I think it has a lot of things going for it, that make it a great photo subject:

1) Symmetrical, but not perfectly
2) If you center it horizontally in the viewfinder, with just about any zoom, you get a nice "rule of thirds" composition.
3) It comes off with a nice "rule of thirds" horizon if you center the formation in the viewfinder
4) Great framing (no power lines, other rock formations, etc. - just nature.)

and most importantly

5) It just plain looks great, with an excellent Western character, great color, and with great Arizona light at sunset.