Inside the cliffs of the Grand Canyon

 In some approaches to the Grand Canyon, you find yourself inside the Canyon walls without realizing the change. The Canyon is so vast that it feels like the walls of the Canyon are rising and that you are not really entering the Canyon. From above, these huge cliffs would be easily identified as part of the Canyon complex. But the huge flat plain you are traveling over is so vast, you cannot comprehend that the Canyon could include your travels.