Mars is a weird place. I mean, really. What kind of normal planet would have a huge flat valley cutting right through the north polar ice cap?
This picture [click to barsoomenate] is a combination of shots taken from 2002 - 2005 by the spacecraft Mars Odyssey, using a camera called THEMIS, which takes images in visible and infrared light. The valley is called Chasma Boreale (literally, northern chasm) and is formed by retreating ice in the cap. Over eons of time, as the cap evaporated and reformed, sand got caught in layers in the ice. Now, as the cap retreats again, the sand is released into the valley floor. You can see the layers in the valley wall in the image, and also dunes as the wind piles it up.
The valley is pretty deep: the walls can be as high as 1.4 kilometers (almost 0.9 miles)! That would be interesting to ski, especially in Mars's lower gravity (0.38 of Earth's). Of course, to get to this butterscotch valley, you'd have to travel through the seven levels of the Candy Cane forest, and through the sea of swirly twirly gum drops*.
Image Credit: NASA/JPL-Caltech/ASU
* Someone must get this joke.