What is "plinius"

Plinius is a prominent lunar impact crater on the border between Mare Serenitatis to the north and Mare Tranquilitatis to the south. South-southeast of Plinius is the crater Ross, and to the northeast is Dawes. Just to the north is a system of rilles named the Rimae Plinius. At the northwest edge of the rille is the Promontorium Archeruia, a cape off the western rim that encloses the Mare Serenitatis.

The sharp rim of Plinius is slightly oval in form, with a terraced inner wall, and an irregular outer rampart. It lacks a visible ray system. The crater floor is hilly, and in the middle is an irregular central peak that has the appearance of a double crater formation under certain angles of illumination. There is a cleft feature attached to the northern side of the peak. The eastern half of the floor is much more smooth and level than the hummocky west, and this section forms a crescent shape about the central peak.