Ploërmel astronomical clock, Astronomical clock in Ploërmel, France.

The Ploërmel astronomical clock is housed in the motherhouse complex and displays the movements of celestial bodies throughout the entire year. It features ten separate dials that track different phenomena such as lunar phases, planetary positions, and solar movements.

Brother Bernardin, born Gabriel Morin (1812–1876), a mathematics and astronomy teacher with no clockmaking training, built the clock with his students between 1850 and 1855 in the congregation's workshops. It was moved in 1890 into a glazed octagonal kiosk in the cloister. It was restored in 1920 and 1979 and classified as a monument historique on 25 June 1982.

Brother Bernardin, a mathematics, astronomy and navigation teacher with no clockmaking training, built the clock from 1850 to 1855 with his pupils in the evenings, forging the parts in the congregation's own workshop. It began as a classroom teaching aid, and since 1890 it has stood in a glazed octagonal kiosk in the cloister between the Lycée La Mennais and the congregation's buildings, where it is viewed from outside.

The clock is located inside a religious building complex, so visitors should check access conditions and opening times before arriving. The building is relatively easy to locate as it sits in the town center.

Each of the ten dials operates independently to track different celestial phenomena, including lunar phases, planetary positions, and solar movements.