To be privately owned
Oberpöllnitz Castle

Oberpöllnitz Castle, a round castle, rises in the higher part of Oberpöllnitz in Thuringia. Its almost circular shape gives it an architectural identity.
History+
The first documented mention of the castle dates back to 1341, where it was described as a “round building with a small inner courtyard”. In the 16th century, under the Lords of Pöllnitz, it was converted into a Renaissance castle, whose design elements such as volute gables and obelisks are still partly recognizable today, although many decorative elements inside are destroyed. A keystone at the gate entrance indicates a renovation in 1848 and states the year of construction as 1414. Further structural changes followed in the 19th and 20th centuries. From 1928, the Reichstag deputy Albert Abicht was the tenant of the associated manor. A threatened demolition of the dilapidated castle was averted in 1977, but the decay continued until parts of the outer walls and roof collapsed in the 1980s. From 1992, the German Foundation for Monument Protection supported the restoration of the slate roof, walls, and interior ceilings.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://schloesserrundschau.de/thueringen/schloesser/saaleorla002.html
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: 50.7492, 11.8816