A marsh or marshland castle () is a type of lowland castle that is situated in marshy or boggy countryside. It uses the natural inaccessibility of the terrain to its defensive advantage. Examples of well-known marsh castles in Germany include: * Weferlingen Castle, a ruined castle in Oebisfelde-Weferlingen in the state of Saxony-Anhalt. * Oebisfelde Castle, the oldest surviving marsh castle in Germany, also situated in Oebisfelde-Weferlingen in Saxony-Anhalt. * Storkow Castle, in Storkow the state of Brandenburg. * Calvörde Castle, in Calvörde in the state of Saxony-Anhalt.