The Nereidum Montes is a mountain range

Mountain range

A mountain range is a single, large mass consisting of a succession of mountains or narrowly spaced mountain ridges, with or without peaks, closely related in position, direction, formation, and age; a component part of a mountain system or of a mountain chain...

 on Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

. It stretches 3,677 km, northeast of Argyre Planitia

Argyre Planitia

Argyre Planitia is a plain located in the Argyre impact basin in the southern highlands of Mars. Its name comes from a map produced by Giovanni Schiaparelli in 1877; it refers to Argyre, a mythical island of silver in Greek mythology....

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There is a crater at 45.1°S, 55.0°W on the Nereidum Montes that is similar to Galle

Galle (Martian crater)

Galle is a crater on Mars. It is located on the eastern rim of the huge impact basin Argyre Planitia. It is named after the astronomer Johann Gottfried Galle....

 in that it also has a smiley face pattern on the crater. However, it is much smaller than Galle itself.

Gullies

Gullies are common in some latitude bands on Mars. Usually, gullies are found on the walls of craters or troughs, but Neredium Montes has gullies in some areas. See the image below. Gullies occur on steep slopes, especially craters. Gullies are believed to be relatively young because they have few, if any craters, and they lie on top of sand dunes which are young. Usually, each gully has an alcove, channel, and apron. Although many ideas have been put forward to explain them, the most popular involve liquid water either coming from an aquifer

Aquifer

An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...

 or left over from old glaciers

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

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