It's strange to see the Red Planet as a Blue Marble. Continents and seas take shape, familiar and yet alien.
Western Hemisphere Then:
Above is Kevin Gill's assessment of how the western hemisphere of Mars would look either terraformed by human hands or returned to its ancient state. You can see Olympus Mons off to the left, the volcano three times the height of Everest reaching towards the sky. The open maw of the Valles Marineris canyons dominate the center of the concept art.
Western Hemisphere Today:
Southern Hemisphere Then: