Gneisenau Castle, Heritage castle in Kleinzell im Mühlkreis, Austria.

Gneisenau Castle is a stone structure in Kleinzell im Mühlkreis featuring traditional Austrian architectural elements. The building combines residential and defensive sections, typical of noble estates found in this region.

The castle originated as a residence for a noble family and was inhabited and modified across generations. Its protected status reflects its historical importance to Upper Austria's architectural heritage.

The Neithart family, originally from Ulm, took the name "von Gneissenau" in the 18th century; Cardinal Johann Eberhard Neidhardt and Prussian field marshal August Neidhardt von Gneisenau came from this line. Since 1959 the castle has housed a district old people's home, so the historic rooms are in everyday use rather than museum display.

The castle sits in Kleinzell im Mühlkreis at the address Weigelsdorf 14, situated on hills in the region. Before visiting, check with local tourism offices about accessibility and viewing options.

The castle sits among several medieval structures in the region that together form a network of historical sites. This clustering shows how widespread noble estates were across Upper Austria.