Water has left its mark in a variety of ways in this martian scene captured by ESA’s Mars Express.

Arda Valles context
The region lies on the western rim of an ancient large impact basin, as seen in the context map. The image shows the western part of the Arda Valles, a dendritic drainage system 260 km north of Holden Crater and close to Ladon Valles.

Vast volumes of water once flowed from the southern highlands, carving Ladon Valles and ponding in the large Ladon Basin seen in this image.

The plan views show the striking dendritic drainage pattern of the valleys (left). Many contributing streams merge into tributaries of the main channels before flowing down into the smooth-floored impact basin towards the right.

More information at: ESA – Footprints of a martian flood