Rummu Quarry is a submerged limestone quarry located in Rummu, Estonia. However, it was established as a prison in January 1938. In the same year, after the mining of the Vasalemma limestone began, a quarry was also founded and it became a penal colony and a prison camp. When the limestone and marble industries gained importance, the prison inmates were used as a source of labor. The original name of the prison was Murru, the name Rummu is affiliated with the area much larger than the actual prison area. The prison was closed in January 2013.
During the Soviet era, until the 1990s, excavation and mining were performed as hard labor by Rummu prisoners, who would excavate limestone from the water-drained quarry.
At first, the prison was turned into a quarry where up to 400 inmates would work daily. As the demand for limestone decreased in the 1970s, the inmates were redirected into the wood and metal industries by the Soviets. The prison grounds served as the production ground for several factories and also catered to the needs of the military industry.
Work in the quarry created an overflow of water that was pumped into a kilometer-long ditch that provided water to the Rummu settlement and irrigation for the nearby fields. After Estonia became independent, the concept of forcing inmates to work ended, and the quarry was abandoned. Since the redirection of the water overflow stopped, water levels started to rise. Over time, the prison almost wholly filled with groundwater and formed a lake.
After it was shut down, the area became popular for water sports enthusiasts, nature photographers, and tourists.
