It's a crater on Mars, and it's as close to a photo-realistic map as your gonna get in Ace of Spades :)
This was made (and posted) a few months ago by JUSTICE and myself, using raw data from Victoria Crater on Mars.
Thought it was due for a repost:
Big Image (Dany0 made this beautiful iso-render):
http://i.imgur.com/CUpTm.png
Download:
http://www.thisisnotsciencefiction.com/victoriaplus.vxl