Vallis Snellius (Moon)

Named from nearby crater.

Vallis Snellius is a linear valley on the near side. This feature is radial to the Mare Nectaris basin to the west-northwest, much like Vallis Rheita to the southwest, and the two likely share a common origin. Although linear, this valley is irregular in shape and has been heavily worn by impact erosion, making it difficult to trace across the surface. (wikipedia entry)

A vallis is a valley. On the Moon they are named after nearby craters or other landforms.