As noted, this type of castle was extremely common. Harburg (Horeburg/near Hamburg), the first castle at Danzig are perhaps the most famous of these. They were most often built along the Northern European plains on the South shore of the North sea and the Baltic Sea. But that is only indicating that a lot of wetlands can be found in those regions. They ...


Calvörde Castle in Saxony-Anhalt is an example of a rather common (to my great surprise) phenomena - the Marsh Castle. It guarded transportation routes between Brandenburg, Brunswick, and Magdeburg.


Winchester cathedral was build by driving oak trees in to the marsh. The stone walls were then laid on top. It managed 900 years before the foundations needed to be reinforced with concrete.

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