Mlawa
Just on the outskirts of Mlawa, on 17 January 1945, the Gestapo murdered 364 Polish resistance fighters, political prisoners and Soviet prisoners of war.
Current status: Monument (2012).
Location: 53°06'12.81"N 20°21'41.37"E
Get there: Car.
Follow up in books: Lukas, Richard C: Forgotten Holocaust: The Poles Under German Occupation 1939-1944 (2008).
A mausoleum has been established for the victims on the site.