To be privately owned
Lichtenhag Castle

The Lichtenhag Castle Ruin, a former hilltop castle, stands on a steep ridge above the valley of the Große Rodl in Upper Austria.
History+
The first documented mention of Lichtenhag Castle occurred in 1167, naming Leuthart and Chunrad de Hage as its owners. The Hager family, later known as Aspan von Lichtenhag, held the lordship until 1615. In that year, the castle was sold to Wolf von Gera. A description from 1615 lists, among other things, a large parlor, chambers, a kitchen, a cellar, and stables for ten horses. At that time, the lordship also included forests, Fischbach, a manor farm, and 47 subjects. By the mid-17th century, the castle was inhabited only by tenants. In 1654, Konrad Balthasar Starhemberg acquired Lichtenhag along with Eschelberg and Waxenberg castles. Administration was moved to Eschelberg, and Lichtenhag Castle began to fall into disrepair. By around 1674, the residential tower was already a ruin.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Lichtenhag-1.jpg
This description draws on the facts documented in the linked Wikipedia article; Wikipedia content is licensed under CC BY-SA 4.0. Wording and editing: Mobile History.
Location: 48.3794, 14.1756