I've been staring at this image on the background of my desktop for some months now and I can't bear to change it out for a new image. I usually change every 3-4 days!
So much can be seen on this volcanic cone. First of all, it is located in Indonesia, and the background history ( at least for man's span of existence) can be found at http://volcano.oregonstate.edu/vwdocs/volc_images/southeast_asia/indonesia/krakatau.html
You can see every lava flow outlined clearly. Each lobe is defined. The segment of trees wiped out by the recent flow is clearly seen. The windward side clearly receives most of the energy of the waves, as there are no sediments accumulating there. On the lee side of the island, the beach deposits are clear.
If the resolution allows, you can make out a narrow trail that scientists must be using to reach the summit for their gas sampling.
The white areas are likely ash (too warm for snow there??) , whereas the rusty brown areas probably represent a highly oxidized (rusted) flow or ash fall.