According to legend, the water should never dry out in this depression.
Visited April 2019
Image credit: Uwe Häberle 04/2019
According to legend, the water should never dry out in this depression.
Visited April 2019
A German bullaun stone perhaps.
Not sure, it might be natural, see also pictures of
Marienborn 1 ->
themodernantiquarian.com/site/19137/marienborn_1.html
and
Helmstedt 1 and 2 ->
themodernantiquarian.com/site/18887/helmstedt.html
or
Süpplingenburg ->
themodernantiquarian.com/site/19131/spplingenburg.html
The stones are local lignite quartzite, which looks quite different to the boulders in northen part of Germany (e.g. Emsland).