Marienstern Abbey, Gothic monastery in Mühlberg/Elbe, Germany

Marienstern Abbey is a former Cistercian nunnery in Mühlberg/Elbe. Its church is a single-aisled, five-bay Brick Gothic building begun around 1225/30, with a two-bay choir and polygonal apses on the choir and transepts. The south transept front has a pointed-arch portal framed in sandstone and brick, and a polygonal stair tower added in 1576.

The monastery was founded in 1228 with support from Henry III, Margrave of Meissen, who approved the conversion of the parish church.This early patronage by the margraviate shaped the site's development over several centuries.

The name Marienstern means "Star of Mary"; the abbey was formerly also called Güldenstern. Since 2000, Claretian missionary brothers have lived in the former abbey premises on behalf of the Bishop of Magdeburg, Gerhard Feige, seeking to revive the monastery dissolved in 1539. The 1566 winged altar from the abbey church is now in Mühlberg's town church.

The former abbey church, now the old town parish church, was restored from 1992 with support from the Deutsche Stiftung Denkmalschutz. The roof turret over the crossing, rebuilt after 1991, was destroyed again by a storm on 24 May 2010. The refectory, altered for agricultural use in 1820, has also been under restoration since 1992.

The monastery's refectory dates from the 13th and 14th centuries but was completely transformed in 1820 for a new purpose.This change shows how a building adapted to serve different needs across the ages.