The building at Uniwersytecka Street, location of the Museum of Martyrdom “Under the Clock”, was constructed for the District Land Office in 1930. In January 1940, the building was taken over by the Office of the Commander of Security Police and Security Service, and became the headquarters of the Geheime Staatspolizei (Gestapo) – Secret State Police. Its task was to fight the internal enemy of the Third Reich – Poles involved in the resistance movement and the elite of the Polish nation.

The building became the place of the most cruel tortures. People brought for interrogations that took place in special rooms on its upper levels called it “Under the Clock”. A prison for political prisoners was organised in the basement. It consisted of 12 cells, 2 dark rooms, a solitary, a utility room and a room for German guards. The dimensions of most of the cells were 340 x 279 x 238 cm. The solitary, the larger cell no. 12 and one dark room stood out from the rest. The dark room was only 75 cm wide.

The windows in the cells were boarded up and buried with ground, preventing prisoners from contact with the outside and significantly limiting the air supply. The doors to each of the cells (except the dark rooms) were replaced with bars. The cells were not heated. The only sources of light was located in the corridor. The cell’s equipment consisted of one bench or bunk. Water was dripping from the pipes under the ceiling, insects were widespread. Interrogations began around 9 AM. Despite thick walls, screams of the victims of tortured reached the cells. It is estimated that between 1942 and 1944 ca 200 people were murdered here.

After the German evacuation from Lublin on 22 July 1944, the prison at Uniwersytecka Street was taken over by the Soviet secret police. Afterwards, the building was handed over to the Polish People’s Army.
On 23 September 1979, due to the efforts of the Club of Former Political Prisoners of the Lublin Castle and “Under the Clock” and its cooperation with the District Museum in Lublin (now the National Museum in Lublin), the Museum of Martyrdom “Under the Clock” was officially opened. In 2017, the cells were renovated and a new exhibition was opened.