Princes' House, Royal summer residence in Plön, Germany.

The Princes' House in Plön is a former garden palace whose central pavilion was built from 1744 to 1751 by Johann Gottfried Rosenberg for Duke Frederick Charles. In 1895 it was enlarged by about three times with two side wings to house six imperial princes, and the Marble Hall became a schoolroom. The interior stucco work is by Bartolomeo Bossi.

The core pavilion was built from 1744 to 1751 by Johann Gottfried Rosenberg for Duke Frederick Charles of Schleswig-Holstein-Plön as a private garden retreat. After the duchy reverted to Denmark in 1761 it stood largely empty, later serving as a forester's home and a chaplain's residence. In 1895 it was enlarged with two side wings to house the six sons of William II, who moved in on 18 April 1896.

The name Prinzenhaus dates from its use as home and school for the six sons of Kaiser Wilhelm II from 1896; Crown Prince Wilhelm and Prince Eitel Friedrich moved in on 18 April 1896. The Marmorsaal was converted into a classroom, and a teaching farm was set up on the Prinzeninsel. Today the Plön registry office runs a wedding room in the building, and concerts are held there.

The house is typically accessible through guided tours offered by local heritage organizations, so it is worth checking ahead before visiting. The rooms may have narrow stairs and doorways typical of older buildings, so wear comfortable shoes and allow time to explore thoroughly.

The princes' lessons extended beyond the classroom: a model farm was laid out on Princes' Island in the Plön lake, where Crown Prince Wilhelm and his brothers learned practical agriculture. A dedicated Prinzenbahnhof was also built below Plön Castle for the imperial family's journeys.