The Treblinka I Labour Camp was established in the summer of 1941 near a pre-war gravel pit, located within the triangle formed by the villages of Maliszewa, Poniatowo and Wólka Okrąglik, approximately 6 km from Treblinka railway station. In the years 1940–1941, a concrete road connecting Małkinia and Kosów Lacki was constructed using materials extracted from the local gravel pit. The district governor (Landrat) in Sokołów Podlaski, Ernst Gramss, established a company producing concrete based on resources obtained from the gravel pit. Difficulties in obtaining cheap labour had a significant impact on the establishment of the labour camp. One of the main reasons for imprisoning inmates in this camp was the need to discipline the Polish population under German occupation into delivering compulsory quotas on time.

The establishment of the Treblinka I Labour Camp was formally sanctioned by an ordinance issued on 15 November 1941 by the Governor of the Warsaw District, Ludwig Fischer. The camp covered an area of 16.57 [1] hectares. It was staffed by members of the SS: approximately 20 Germans and Austrians, as well as around 100 guards [2], primarily of Ukrainian origin. The commandant throughout the entire period of the camp’s operation was the German Theodor van Eupen.

It is estimated that approximately 10,000 prisoners—Poles, Jews and Roma—were murdered in the Treblinka I Labour Camp or died as a result of disease, exhaustion, and the harsh conditions [3]. The number of prisoners held in the camp at any one time is difficult to determine; it is estimated to have been approximately 1,000–2,000 [4].

Prisoners worked primarily in the gravel pit, extracting and loading materials, at the railway station in Małkinia, regulating the Bug River, and within the camp itself. Some were assigned to assist on a farm taken over by the Germans, known as “Milewek”, located approximately 500 metres to the west of the camp, which produced food for the camp.

Initially, prisoners sent to the camp were mainly residents of the Sokołów and Węgrów counties, including farmers punished for failing to fulfil compulsory deliveries (quotas). Poles were imprisoned for periods ranging from two to six months or indefinitely. Jews were usually executed or held indefinitely under harsh conditions. The majority of Roma and Sinti were murdered at the Execution Site without being registered as prisoners of the labour camp [5]. Polish political prisoners, including those from Pawiak prison and Aleje Szucha in Warsaw [6], were also executed at the Execution Site. From 1942 onwards, a clear division between Polish and Jewish prisoners was introduced [7]. During the operation of the Treblinka II Extermination Camp, there were cases of Jewish transports being directed directly to the labour camp, as well as instances of prisoners from Treblinka I being murdered in the gas chambers of Treblinka II [8].

The liquidation of the camp began on 23 July 1944. In the evening, Polish prisoners were locked in a barrack, while approximately 550 Jewish prisoners were taken out of the barracks and almost all were shot in a nearby forest. The last executions were most likely carried out on 1 August 1944 [9], when approximately 20 Polish prisoners were shot, and the remaining prisoners were released. Not all managed to return home; some were so exhausted that they died on the way [10]. The German staff destroyed the documentation, removed the property gathered there, and set fire to the barracks.