The most noticeable feature of The Grand Canyon is its size. It is very large and very deep. It’s the sort of scale that can not yet be transmitted through screens. It simply covers too much of your field of vision and the walls are just too far away for your depth perception to register the astonishing distances.
The Grand Canyon is so big that, not only is your depth perception useless, but the parallax effect seems to brake. The shift in perspective that your legs achieves is just so tiny compared to the depths of the landscape. The view of the canyon just sort of floats around you as you walk along the edge. Much like a starry sky but carved into the ground.