. It aims at commemorating individual persons at exactly the last place of residency—or, sometimes, work—which was freely chosen by the person before he or she fell victim to Nazi terror, euthanasia, eugenics, was deported to a concentration or extermination camp, or escaped persecution by emigration or suicide. s of 31 2017 , over 56,000 "stolpersteine" have been laid in 22 European countries, making the "stolperstein" project the world's largest decentralized memorial.