The crater is named after the Roman natural scientist and author Pliny the Elder.

At the northwest edge of the rille is the Promontorium Archerusia, a cape off the western rim that encloses the Mare Serenitatis.

[2] The sharp rim of Plinius is slightly oval in form, with a terraced inner wall and an irregular outer rampart.

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.

By convention, these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Plinius.