Rummu Underwater Prison

It's unlikely that those interred in this Soviet prison ever imagined that the quarry they were forced to work in would someday become a beautiful diving spot. But it's a weird world, and time is long. 

The ruins of the abandoned prison camp outside the small Estonian town of Rummu were once a dreaded stone edifice, but are now a beach attraction. The prison was already established in the 1940s by the Soviet Union. It was built in a convenient location, on the lip of a limestone quarry in which the inmates were forced to toil. 

The seemingly impenetrable walls of the prison were not to last forever. When Estonia regained its independence in 1991, the Soviets moved out and many of their institutions fell, including the labor prison at Rummu. Both the prison and the quarry were abandoned in the changeover.

Without anyone to look after the natural groundwater that seeped into the former quarry, it soon filled up with water, creating a new lake with alarming speed. It filled up so fast that many of the mining machines and even some of the buildings were swallowed whole by the rising waters. 

Today, some of the former prison can still be seen on land, as parts of the structure stick out from the crystal clear lake waters. The spot has become a prime location for divers and adventurous beachgoers who come for the sunken ruins beneath the waves.