The Maja Valles are a large system of ancient outflow channels in the Lunae Palus quadrangle on Mars.

[2][3] Huge outflow channels were found in many areas by the Viking Orbiters.

They showed that floods of water broke through dams, carved deep valleys, eroded grooves into bedrock, and traveled thousands of kilometers.

[4][5][6] The Maja Valles show evidence of lava flows in the northern section.

Studies with HiRISE and CTX images suggest that the lava flows did not reach the turbulence necessary to erode large channels.