To be privately owned
Windegg Castle

Approximately three kilometers north of Schwertberg in the Perg district of Upper Austria, the castle ruin Windegg, also known as Windeck, is located. It is an example of Romanesque ashlar masonry, a rare construction style in this region.
History+
The construction of Windegg Castle took place in the 13th century. The first documented mention dates back to 1208, when Dietrich de Windeckke held its administration. Between 1267 and 1313, Leuthold I von Kuenring was recorded as the feudal lord of the Regensburg property, having the castle managed by stewards. In 1354, Leuthold III von Kuenring sold the dominion to Ulrich and Eberhard von Kapellen. After several changes of ownership, the castle came into the possession of the Wallseer in 1410. Following the death of Wolfgang von Wallsee in 1483, his daughter Barbara, married to Count Siegmund von Schaunburg, inherited the complex. In 1557, Christoph von Tschernembl acquired the castle. Through the purchase of Schwertberg Castle by his son Hanns von Tschernembl, the two lordships were united. From 1675, the castle began to fall into disrepair, serving primarily as a storage facility. The ruin underwent extensive renovation by a local castle association starting in 1980.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Bergfried_Burgruine_Windegg.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: 48.2939, 14.5967