Two pictures here: one of the very small and one of the very large.
The first photo shows the Sloan Great Wall, arguably the largest structure in the universe. Not a very glamorous photo, but what it represents in astounding. It's over one billion light years long.
http://antwrp.gsfc.nasa.gov/apod/ap071107.html
The second photo was taken with a scanning tunneling microscope of an array of nickel atoms.
http://nobelprize.org/educational_games/physics/microscopes/scanning/gallery/2.html
