from Wikikedia:
"A Stolperstein (pronounced ˈʃtɔlpɐˌʃtaɪn; plural Stolpersteine; literally ‘stumbling stone’, metaphorically a ‘stumbling block’) is a sett-size, ten-centimetre (3.9 in) concrete cube bearing a brass plate inscribed with the name and life dates of victims of Nazi extermination or persecution.
The Stolpersteine project, initiated by the German artist Gunter Demnig in 1992, aims to commemorate individuals at exactly the last place of residency—or, sometimes, work—which was freely chosen by the person before they fell victim to Nazi terror, euthanasia, eugenics, deportation to a concentration or extermination camp, or escaped persecution by emigration or suicide. As of December 2019, 75,000[1] Stolpersteine have been laid, making the Stolpersteine project the world’s largest decentralized memorial."
