NASA published in Instagram a snapshot of the traces of Martian rivers. The photos are taken as part of the mission Mars Reconnaissance Orbiter (MRO).
They are visible ancient river channels, which like the walls high protrude above the surrounding surface. Probably, this was due to the fact that centuries-old sediments of river water, which formed the bottom of rivers, were more resistant to erosion. The soft rocks surrounding the riverbeds have faded over time, and now one can clearly see a section of the rapid geological past of the Red Planet.