Otwock [ˈɔtfɔt͡sk] ⓘ (Yiddish: אָטוואָצק) is a city in the Masovian Voivodeship in east-central Poland, some 23 kilometres (14 mi) south-east of Warsaw, with 44,635 inhabitants (2019).

Otwock, which is located along the line, became a popular suburb, with numerous spas and several notable guests, including Józef Piłsudski and Władysław Reymont, who wrote his Nobel Prize-winning novel Chłopi there.

Following the German–Soviet invasion of Poland, which started World War II in September 1939, the town was occupied by Germany.

A murderous Action T4 euthanasia program was carried out by the Nazis in the local Zofiówka Sanatorium for the psychiatric patients[2] in order to confine its Jewish population for the purpose of persecution and exploitation.

[3] The Ghetto was liquidated between August and 19 September 1942, when 75% of its Jewish population of 12,000–15,000 numbering at around 8,000 were assembled by the Nazis at a layover yard in Otwock (pictured) and transported in cattle trucks to extermination camps in Treblinka and Auschwitz.

[5] Otwock is the hometown of Irena Sendler (1910 – 2008), the Polish humanitarian who saved thousands of Jewish children during the Holocaust; as well as Krystyna Dańko, both awarded the titles of Righteous among the Nations by Yad Vashem.