Once the MSL has achieved most of its mission objectives, and happens to be sitting close to a flat stone surface with plenty of rocks in easy reach of the manipulator arm, I would urge the rover team to consider building a cairn. This could be of interest to the press and public: "The first human-built structure on another planet." It would also be a "monument to Curiosity" likely to last thousands of years. Stone cairns can be found wherever humans have trekked along rocky paths. In the Andes, Alps and Nepal they can be thousands of years old, or just assembled yesterday. The timelessness of a cairn is one of its attractions. As I look out across the Atacama-like wastes of Gale Crater, I feel an overwhelming urge to build a cairn.