In eastern Ismenius Lacus, lies Mamers Valles, a giant outflow channel.

The channel shown below goes quite a long distance and has branches.
 It ends in a depression that may have been a lake at one time.
 The first picture is a wide angle, taken with CTX; while the second is a close up taken with HiRISE.
In eastern Ismenius Lacus, lies Mamers Valles, a giant outflow channel.
The channel shown below goes quite a long distance and has branches.  It ends in a depression that may have been a lake at one time.  The first picture is a wide angle, taken with CTX; while the second is a close up taken with HiRISE.
Ismenius Lacus quadrangle