Meanders in Ridge Form in the Zephyria Region

In this image from NASA Mars Reconnaissance Orbiter spacecraft, an ancient sinuous meandering river system is surrounded by features called yardangs. The yardangs are the ridge-like landforms that align approximately north-south. These features were created as the wind scoured and eroded the bedrock. The raised relief of the meandering river suggests inverted topography, likely due to lithification and cementation of the riverbed sediment.