Lattice plane structure of Zeolite, with a 2nm spacing - Horizontal Field Width: 254 nm
FEI is running a micrograph contest. They have quite a collection of images. This image is not that impressive on a visual basis, but it is on a technical one. The magnification factor is 5 million. The lighter areas in the image are gaps where some molecules can go, but others can't. That's pretty darn small.
Zeolite Part 1.
Zeolite Part 2.