Piccolomini is a prominent lunar impact crater located in the southeastern sector of the Moon.

The crater is named after 16th century Italian Archbishop and astronomer Alessandro Piccolomini.

The lengthy Rupes Altai begins at the western rim of Piccolomini, curving to the northwest.

These structures have been somewhat smoothed by landslips and erosion, most likely induced by seismic activity.

[4][5] By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Piccolomini.