Saguaro cactus are not the largest in the world, but they are the largest in the desert in Arizona. I have noted before that saguaro have become identified with the idea of desert to the extent that they have been included in graphics for areas where saguaros do not grow, such as Monument Valley in Northern Arizona. One interesting thing about this beautiful specimen are the visible annual growth rings around the arms and central stem of the cactus. A cactus like this is like more than 200 years old. You have to understand that the arms grow after the stem is already 20 or so feet tall. The saguaros in the background are only about 75 to 100 years old.