We’ve been in Berlin for a few days. Walking along a residential street in Prenzlauer Berg I came on these brass squares outside the door of an apartment block and suddenly realised what they were: Stolperstine, literally “stumbling stones”, memorials to people, mainly Jews, who once lived in that building and who were deported and murdered by the Nazis. These three commemorate the Holzmann family — father Fritz, mother Dora and son Gerhard — who were all deported on the same day, 29 October, 1941. Father and son went to a forced labour camp and were murdered within a month of one another in 1943. Dora was murdered in another camp in May 1942. According to Wikipedia, over 50,000 stolpersteine have been laid in 18 European countries, making the stolperstein project the world’s largest decentralised memorial.