NASA's Curiosity Mars rover has been exploring a region on Mars filled with unique geologic formations called boxwork, which are low ridges with sandy hollows in between. These formations suggest that ancient groundwater once flowed in this area of the planet. The rover has been studying this region for about six months.

Source: https://www.nasa.gov/missions/mars-science-laboratory/curiosity-rover/nasas-curiosity-rover-sees-martian-spiderwebs-up-close/