Sobibor was an extermination camp built and operated by Nazi Germany as part of Operation Reinhard. It was located in the forest near the village of Sobibór in the General Government region of German-occupied Poland.
As an extermination camp rather than a concentration camp, Sobibor existed for the sole purpose of murdering Jews. The vast majority of prisoners were gassed within hours of arrival. Those not killed immediately were forced to assist in the operation of the camp, and few survived more than a few months. In total, some 170,000 to 250,000 people were murdered at Sobibor, making it the fourth-deadliest Nazi camp after Belzec, Treblinka, and Auschwitz.
Wikipedia https://en.wikipedia.org/wiki/Sobibor_extermination_camp
Address (Unnamed Road), 22-200, Poland
Coordinates 51°26'50.725" N 23°35'35.837" E