Mare Anguis (Moon)

"Serpent Sea"

Mare Anguis is a lunar mare located on the near side , about 150 kilometers in diameter. Located within the Crisium basin, Mare Anguis is a part of the Nectarian System, meaning that it was formed during the Nectarian time period. Like most mare, the surface is dark, indicating that it has been filled with volcanic basalt. (wikipedia entry)

A mare is a "sea" or large circular plain. On the Moon they are named after latin terms describing weather and other abstract concepts.