Agreed Gayle, the light here is indeed "unusual". Mesa Arch is located in Canyonlands National Park near Moab, Utah. On clear days in the early morning light, the underside of this arch is illuminated and truly "glows". It was well worth the pre-dawn awakening and forty minute drive to this spot. The morning I was made the trek, there was only one other photographer there. He told me that the morning prior, there were eight or ten photographers competing for tripod space.