Information: Wikipedia

A Stolperstein literally "stumbling stone", metaphorically a "stumbling block" is a sett-size, 10 by 10 centimetres (3.9 in × 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 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. As of 29 March 2018, over 67,000 Stolpersteine have been laid in 22 countries, making the Stolpersteine project the world's largest decentralized memorial.

The majority of Stolpersteine commemorate Jewish victims of the Holocaust. Others have been placed for Sinti and Romani people (then also called "gypsies"), homosexuals, the physically or mentally disabled, Jehovah's Witnesses, black people, members of the Communist Party, the Social Democratic Party, and the anti-Nazi Resistance, the Christian opposition (both Protestants and Catholics), and Freemasons, along with International Brigade soldiers in the Spanish Civil War, military deserters, conscientious objectors, escape helpers, capitulators, "habitual criminals", looters, and others charged with treason, military disobedience, or undermining the Nazi military, as well as Allied soldiers.

Born in Gulpen, 4 September 1856 – Died in Sobibor, 16 April 1943.  Reached the age of 86 years.

Born in Uden, 24 September 1895 – Died in Sobibor, 23 July 1943.  Reached the age of 47 years.

Born in Gorinchem, 9 April 1894 – Died in Sobibor, 23 July 1943.  Reached the age of 49 years.

Antoinetta was married to Louis van Zwanenbergh. The couple had at least two children: David and Catharina.

Born in Den Bosch, 19 April 1862 – Died in Sobibor, 14 May 1943.  Reached the age of 81 years.

On April 9, 1943, Leentje Seijffers is arrested. Because camp Vught is becoming overcrowded, the elderly and families with more than 3 children are transported to Westerbork. This also applies to Helena Seijffers, who is transported to the 85 infirmary in Westerbork. It consisted for the most part of the sick and the elderly. All were killed immediately upon arrival in Sobibor on 14 May 1943. Leentje was just 81 years old at the time.