Schloss Agathenburg, Baroque château and museum in Agathenburg, Germany.

Schloss Agathenburg is a plain three-story brick building in the Dutch Renaissance style, built as a country estate for Count Hans Christoph von Königsmarck and completed in 1655. A polygonal stair tower stands at the center of the courtyard side, the facade is decorated with blind arcades, and the only ornament is a sandstone portal. The windows are arranged asymmetrically to match the interior layout, with no Baroque symmetry.

Hans Christoph von Königsmarck, a commander in the Thirty Years' War, was made a count and governor-general of Bremen-Verden and built the country house in the village of Lieth; work finished in 1655. He was held prisoner in Brandenburg-Prussia from 1656 to 1660 and died in 1663, so his wife Agathe von Leesten, after whom the house is named, lived here as her main residence. The family kept it until 1694; Hanover bought it in 1740 and used it for the Stade administration from 1753. A fire on 26 April 1921 gutted the interiors, leaving only the outer walls and stair tower.

The name Agathenburg comes from Agathe von Leesten, wife of builder Hans Christoph von Königsmarck; the name was transferred from the old village of Lieth, and locals say those who ignored the new name were whipped while those who used it correctly received a taler. Today the Kulturstiftung runs contemporary art exhibitions, classical and jazz concerts, readings and writing workshops, with a café and museum shop.

The castle stands above a steep geest slope; from the north terrace there is a wide view over the Elbe marsh. The vaulted cellar from the 17th century is being renovated and a lift added so the whole building becomes step-free. The large horse stable now stands to the left of the castle; it was moved here in 1881.

The sculpture garden blends traditional design elements such as boxwood hedges and rose plantings with contemporary artworks. This combination creates an unexpected conversation between historical garden design and modern artistic expression.