This picture is inspired from an excellent Sci-Fi book simply called "Mars" from Mr. Ben Bova. It's also a very deceitful book as it achieves on a big interrogation mark. If you want to know more, read it, I will not say more. This picture is also an answer to people who found my last one not red enough for Mars although, this is not the classical orange "Mars palette". But I hate classical things. ;-) I wanted to drop here a touch of nostalgia, of very old time and melancholy. Eons have passed and what we see, down in the canyon of Marineris might be the last attempt of a civilization to survive on a dying planet. Who were they ? Did they left or perish ? And maybe this might not be a city but simply a natural structure. Give me your ideas ! Technically, I used an elevation file of the canyon of Marineris. With WorldMachine, I added a bit of noise, some terrace and thermal erosion and finally combined the resulting terrain with a mask for the "lost city". (I apologize to Mr. Ben Bova and his readers, as the city is slightly misplaced) Thanks for your comments !