Fredelsloh Abbey, Romanesque monastery in Fredelsloh, Germany

Fredelsloh Abbey is a former Augustinian monastery in Fredelsloh, part of Moringen, of which only the church St. Blasii und Marien survives. The Romanesque basilica is built of Weser sandstone, with two square west towers under saddle roofs, a transept, side apses and a rectangular east choir. Its ornament is limited to arched friezes and cornices; the main portal is on the north transept arm.

This monastery was founded in the early 12th century as a religious community. Shortly after its establishment, it was reorganized to house both male and female communities, becoming an important religious institution in the region.

The church's full name, St. Blasii und Marien, pairs the patron saint of the 1132 foundation, Blaise, with the Virgin Mary, whose patronage was added when the double monastery was created between 1144 and 1146. The northern portal, still the entrance, has a masonry arch from the 1130s. In the choir are masonry reliefs of the apostles.

The west section is separated from the nave by a wall and can only be reached through the west entrance; the main entrance today is the north portal of the transept. The double-helix staircase is not publicly accessible because a supporting wall was built in the 17th century.

Between the two west towers sits a half-round stair turret resembling a west apse, holding a double-helix spiral stair built in the 13th century, probably by a builder from the Levant; a count of Dassel had joined the Third Crusade. A supporting wall added in the 17th century now blocks public access, so the stair can only be seen from outside.