Eggenberg Castle (German: Schloss Eggenberg) in Graz is the most significant Baroque palace complex in Styria. With its preserved accouterments, the extensive scenic gardens as well as some additional collections from the Universalmuseum Joanneum housed in the palace and park, Eggenberg Castle counts among the most valuable cultural assets of Austria. With its construction and accouterment history, it exhibits the vicissitude and patronage of the one-time mightiest dynasty in Styria, the House of Eggenberg. In 2010, Eggenberg Castle was recognized for its significance to cultural history in an expansion to the listing of the Graz Historic Old Town among UNESCO World Cultural Heritage Sites.
The palace lies on the western edge of the Styrian capital of Graz in the Eggenberg district. The northern corner of the palace grounds features the Planetary Garden and Lapidarium of Roman stonework as well as the entrance to the new Archeological Museum, which houses the Cult Wagon of Strettweg. The numismatic collection, located in the former rooms of Balthasar Eggenberger, owner of the imperial minting license and operations in the Late Middle Ages, and the show collection of the Alte Galerie, a collection of medieval through early modern period artworks spanning five centuries of European art history are also housed in the palace itself.