Treblinka was the second-deadliest extermination camp to be built and operated by Nazi Germany in occupied Poland during World War II. It was in a forest north-east of Warsaw, 4 km south of the village of Treblinka in what is now the Masovian Voivodeship. The camp operated between 23 July 1942 and 19 October 1943 as part of Operation Reinhard, the deadliest phase of the Final Solution. During this time, it is estimated that between 700,000 and 900,000 Jews were murdered in its gas chambers, along with 2,000 Romani people. More Jews were murdered at Treblinka than at any other Nazi extermination camp apart from Auschwitz-Birkenau.
Managed by the German SS with assistance from Trawniki guards – recruited from among Soviet POWs to serve with the Germans – the camp consisted of two separate units. Treblinka I was a forced-labour camp whose prisoners worked in the gravel pit or irrigation area and in the forest, where they cut wood to fuel the cremation pits.
Wikipedia https://en.wikipedia.org/wiki/Treblinka_extermination_camp
Address 08-330, Poland
Coordinates 52°37'52.333" N 22°3'10.281" E