Burg Grimmenstein is a medieval fortification situated on a hilltop in the market town of Grimmenstein at 660 meters altitude in the Pittental region of Lower Austria. Originally built in the twelfth century as a defensive structure, it largely deteriorated over centuries until partial reconstruction occurred in the neo-romantic style during the 1960s. Since 2014, private owner Markus Albero Grimmenstein has undertaken comprehensive restoration, achieving approximately 90 percent completion without public funding. The castle reopened to public visitors in April 2016, offering stunning panoramic views of the surrounding landscape and accessible via a convenient slow train service from the valley parking facilities during operating hours.