Schloss Assen, Water castle in Lippborg, Lippetal, Germany

Schloss Assen is a water castle in the Lippe region featuring several towers and defensive structures surrounded by moats. The main buildings follow the Renaissance style of the region and form a connected complex of structures.

The site began as the medieval fortress Borch to Assen, part of the Honsel estate on the Lippe that Emperor Henry II gave to Paderborn's Abdinghof monastery in 1023. The monastery pledged it in 1358 to the brothers Hermann and Themo von Oldendorp. In 1396 Temme von Oldendorp and his wife Katharina sold the castle to Rotger IV von Ketteler; the fief passed to him in 1408, and in 1455 his sons divided the property into Alt-Assen and Neu-Assen.

The name Assen comes from the old "Borch to Assen", first documented in the 11th century. Since 1997 the Servants of Jesus and Mary have used the castle, and from 2001 to 2016 it housed the Kolleg Kardinal von Galen, a boys' boarding school named after Clemens August von Galen, the "Lion of Münster". A bronze statue of the cardinal, seated with the manuscripts of his 1941 sermons, was unveiled in the courtyard in 2007.

The site is used today by a religious community as a center and is not always open to visitors. It is advisable to check in advance whether tours or visits are possible.

The bronze sculpture in the courtyard, unveiled on 8 September 2007 for the boarding school's tenth anniversary, shows Cardinal Clemens August von Galen seated with the manuscripts of his 1941 sermons. It was made by Cologne sculptor Elmar Hillebrand. The cardinal, a great-uncle of the last owner, was beatified in 2005.