There was a gravel pit in the triangle of small villages Maliszewa, Poniatowo and Wólka Okrąglik, in the Sokołów county, 6 km from the Treblinka railway station. It was there that the history of the penal labour camp began.

In September 1939, the German army occupied this area. While preparing for the attack on the Soviet Union, the German authorities paid more attention to this place. A concrete road connecting Małkinia with Kosów Lacki was built at that time, drawing raw material from a nearby gravel pit. At that time, Sturmbannführer Ernst Gramss was the county mayor residing in Sokołów Podlaski. On his initiative, a company was established to produce concrete based on raw material extracted from the gravel pit.

Due to the functioning of the concrete company and the problems it experienced, there was a lack of cheap labour force. After the German attack on the Soviet Union, even gravel extraction was stopped for a short time. It was then that Gramss came up with the idea of setting up the labour camp. It was established in the late summer of 1941. SS-Hauptsturmführer Theo van Eupen became the camp commandant. He was associated with the Military Quartering Administration, which before the attack on the USSR had its seat in Sokołów Podlaski. After a quick march eastwards, the military property gathered in Sokołów Podlaski, Węgrów, Kosów Lacki and the forest camp near Repki remained. Most probably the storage barracks from these places were used for the construction of the camp, which was intended for the “resistant elements” of the Sokołów county and Węgrów county and counted several dozen prisoners in the first days of its existence. It was located in farm buildings at the gravel pit, near the railway ramp, and was managed by local administrative authorities. Officially, the functioning of the camp was sanctioned by order of the Governor of the Warsaw District, Ludwig Fischer, on 15 November 1941.

The functioning of the camp was additionally notified to the public through posters and the Warsaw press – Nowy Kurier Warszawski No. 227 of 22/23 November 1941 and No. 289 of 6/7 December 1941. The German authorities created the impression that only the “criminal element” was put in the camp. The civilians were sent here in retaliation for the armed actions of the Polish underground, for failing to observe the police hour, for suspicion of help to escaping and hiding Soviet prisoners of war, for manifestations of resistance to the representatives of the occupation authorities (e.g. pushing a military policeman).

At first, the camp was called “Arbeitserziehungslager” (Education Labour Camp), later it was officially named “Der SS- und Polizeiführer im Distrikt Warschau Arbeitslager Treblinka”. To differentiate from the extermination camp, which was set up later, the labour camp was named Treblinka I.