Locals call it “the blue lagoon.”
Located in the small Estonian town of Rummu, this popular swimming hole was once a prison. The inmates who were once housed here probably never imagined that the prison would turn into such an awesome attraction.
In 1991, when Estonia gained its independence, the prison, along with the quarry it was built on, shut down.
Soon, a new lake was formed, which eventually swallowed up the majority of the buildings.
Today, the crumbling prison attracts adventure seekers interested in checking out the ruins beneath the turquoise waters, as well as those just looking to cool off during the summer months.