Topographical map of mount everest, using data from the NASA SRTM (shuttle radar topography mission). Approximately 15 miles square.
I haven't done much tweaking on this, but I printed at .27mm layer height with 3 shells and sparse infill (I think 5%) and got decent results. A smaller layer height would probably look better, and more shells should keep flat areas from forming gaps where they recede too far from the previous layer.
And if anyone has a good method for preventing the small blobs from forming on the mountain peaks, I'm all ears.
And speaking of ears, the large flat base is prone to warping, so adding some ears to the corners should help prevent that: http://www.thingiverse.com/thing:38272