Sinus Lunicus (Moon)

"Lunik Bay"-landing area of Luna (Lunik) 2.

Sinus Lunicus is an area of lunar mare along the southeast edge of the Mare Imbrium on the earth's moon. The bay is open to the northwest, and faces the Montes Spitzbergen, a small chain of mountains. The Luna 2 landed in the gap. (wikipedia entry)

A sinus is a small plain. On the Moon they are named after latin terms describing weather and other abstract concepts.