Above the confluence of the Brestanica Stream and the Sava River, Rajhenburg Castle has dominated the area from its 60-metre rocky outcrop for centuries. The powerful owner, Archbishop Konrad of Salzburg, had the castle built between 1131 and 1147, as attested by the oldest Romanesque section. For centuries, the building and the associated estate were managed by the ministerials named after the castle, the Rajhenburgs. This was an influential family which obtained a knighthood title in the 15th century. Their successors added more modern elements and gradually the castle developed its present-day appearance. In 1881, Rajhenburg Castle was bought by Trappist monks and converted into a monastery that remained active until the German occupation in April 1941 when a deportation camp for Slovenians was established in the castle. In 1947, the Trappist order was dissolved, and the castle nationalised. In June 1948, a penal and correctional facility for women was established there, which was later succeeded by other penal institutions. In 1968, an exhibition on Slovenian deportees opened. Ever since, the castle has predominately served as a museum and an event venue. After the denationalisation procedures completed in 2004, the castle became the property of the Municipality of Krško. Today, the fully restored structure is managed by Kulturni Dom Krško. The Museum of Contemporary History of Slovenia is also active in the castle. In 1999, Rajhenburg Castle and its area were declared a cultural monument of national importance.