To be privately owned
Werfenstein Castle

The castle ruin Werfenstein, a former lowland castle, stands in the village of Struden in St. Nikola an der Donau. Its location on the river was once part of a system to block the Danube.
History+
Werfenstein Castle was first documented in 1234. Between 1272 and 1293, Herwicus von Werfenstein is recorded here as a supporter of the Teutonic Order. In 1294, Duke Albrecht II besieged the castle along with the neighboring structures Freienstein and Pain for a period of three weeks. King Rudolf later transferred Werfenstein to Konrad von Sumerau. In 1314, Duke Friedrich pledged the castles of Werfenstein, Hausstein, and Pain to Albert von Volkenstorf, with Heinrich Payr serving as burgrave between 1319 and 1320. The return of the lordships occurred in 1334. In the 15th century, ownership changed hands several times, including Duke Albrecht (1416), Erhard Volkra (1422), and Duke Siegmund of Tyrol (1461). Under Emperor Friedrich III, Werfenstein passed to the brothers Sigmund and Heinrich Prueschenk in 1488. By the end of the 15th century, the castle was abandoned after the Prueschenks moved to the newly built Greinburg. By 1531, the roof was already missing, and in 1645, the dilapidated castle burned down. In 1780, the palas had to be demolished due to the risk of collapse.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Werfenstein_%280%29.jpg?uselang=de
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: 48.2298, 14.8922