Some of the largest sand dunes on earth can be found in Namibia's Namib Desert. My photos of the dunes themselves did not effectively convey their vast size, until I was able to incorporate something else in the picture to give these dunes a sense of scale. The incongruity in scale between the tourists descending the dunes, the man among the trees at the base of the dune, and the vast wall of sand itself tells us how huge these dunes really are.