To be privately owned
Prester Castle

In the Prester district of Magdeburg stands the Prester Residential Tower. This two-story residential tower from the early 16th century, once owned by the patrician Rode family, is now a protected monument.
History+
The construction of the Prester Residential Tower is dated to the beginning of the 16th century. A coat of arms plaque on the tower explicitly states the year 1520 as its construction date. Originally, the building served as the residence of the patrician Rode family.
Source: Wikipedia · Licence: CC BY-SA 4.0 · Image: http://commons.wikimedia.org/wiki/File:Altprester104.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: 52.1013, 11.6754