Le Monnier (Moon)

Named after Pierre Charles Monnier - French astronomer, physicist (1715-1799).

Le Monnier is the remnant of a lunar crater that has been partly inundated by lava flows. It is located on the eastern edge of Mare Serenitatis, and the western part of the rim is missing so that it now forms a large bay. To the north is the crater Chacornac. The interior of this formation is flat and smooth, with no significant craterlets to mark the surface. (wikipedia entry)

A crater is a circular depression likely created by an impact event. On the Moon they are named after deceased scientists, polar explorers, astronauts or cosmonauts.