Burg Ohsen, Water castle in Emmerthal, Germany

Burg Ohsen is a medieval water castle near Emmerthal, built on a rectangular island surrounded by defensive water systems. Stone walls and corner towers form the main structure, creating a barrier between the castle and the surrounding landscape.

Burg Ohsen was probably built around 1200 by the Counts of Everstein to protect the crossing of the southern Hellweg over the Weser; the oldest pottery found there dates from this period. The castle is first documented in 1259, when the count declared he already held it as a fief from the Archbishopric of Cologne and transferred it to the archbishop, taking half back as a fief. After 1351 the Welfs acquired half, and from 1557 the castle was permanently in their possession; today it is privately owned.

The castle's name recalls the old settlement of Ohsen, and its two towers carry their own stories: the smaller one bears an inscription commemorating two women from Tündern burned as witches in 1583, and the Weser-side tower shows the coat of arms of the Counts of Spiegelberg from the first half of the 15th century.

Burg Ohsen is in private ownership and not open to visitors, so there are no tours of the interior. The site lies in Hagenohsen, part of Emmerthal, near Hameln in Lower Saxony. The eastern side arm of the Weser was filled in, so the castle no longer sits on an island; the former water location can still be read from the layout.

The castle is in private ownership and cannot be visited. On the Weser side of the smaller tower, the coat of arms of the Counts of Spiegelberg from the first half of the 15th century is set into the wall. An inscription there also recalls two women from Tündern who were held in the castle on charges of witchcraft and burned in 1583.