Rappottenstein is a municipality in the district of Zwettl, in the Austrian state of Lower Austria. It lies in the Waldviertel, the wooded northwestern quarter of Lower Austria, a rural region of rolling hills and forested terrain along the upper reaches of the Kamp river.
The settlement is best known for Rappottenstein Castle, a medieval fortress founded in the twelfth century and one of the best-preserved castles in Austria. Standing on a rocky outcrop above the Kamp valley, it has never been captured by force and retains much of its original defensive architecture, including walls, towers and a chapel. The castle remains privately owned and is open to visitors.
The surrounding municipality is thinly populated and predominantly agricultural and forested, with tourism centred on the castle and the walking and cycling routes of the Kamp valley. It is connected by road to the nearby towns of Zwettl and Freistadt, and lies roughly 100 kilometres northwest of Vienna.