Unable to answer "What kind of memorial is this?" for https://osm.org/node/336457124 via StreetComplete 54.1:

Apparently Shoah momorial. There is written "Gedenke, Vergiss nie", remember, never forget.

Attached photo(s):
https://westnordost.de/p/181104.jpg
https://westnordost.de/p/181105.jpg