Mawrth Vallis is smack in the middle of a region that has always been mysterious to scientists. This region is the boundary between the southern highlands and northern lowlands of Mars. It is a place where the entire planet suddenly drops in elevation. In effect, Mars is lopsided. Its southern hemisphere is higher in elevation than its northern hemisphere. Mawrth Vallis itself is an ancient channel carved by catastrophic floods. "Mawrth" is the Welsh word for Mars and "Vallis" is Latin for valley. Layered cliffs, which look like Neapolitan ice cream, are rich in clay minerals. Such minerals, called phyllosilicates, form in the presence of water. They may yield information about past environments that could have supported life. Mawrth Vallis is also conveniently near a hazard-free landing zone. The Mars Science Laboratory science team would use the rover to piece together the history of this puzzling site and look for conditions favorable to life.