One of the easy things to do when taking pictures of really big holes in the ground, is to forget to provide a foreground element (or elements) in the picture that offer scale to the shot.
Or, alternatively, one could offer two shots - one that shows the WHOLE scene, and a second shot of the 'interesting element'.
The above is an example of a picture of a tree with the Grand Canyon in the background.
Well, actually, it's the Grand Canyon with a foreground tree for scale. If you click into the picture TWICE, and really run this pic up big, you'll begin to get the idea of the shot. It really needs to be a 16x20 print.
Below are two pictures - the first is the whole scene, for scale ...
And then the 'element shot'.
When you want to show off landscape shots, don't forget to include the elements that offer scale. They make your work more interesting.