Everything about Estonia surprised me. I don’t know what I thought a former Soviet republic in the Baltics would be like. But Rummu Quarry, especially, wasn’t like anything I could have imagined.

I didn’t come to Estonia to dive. But when I heard you can dive in the former Soviet-run prison, now underwater, I knew I had to try it. Built-in the 1940s on a limestone quarry, the prison forced its inmates to work in the mine. With Estonia’s independence in 1991, the Soviets moved out and the prison and quarry were abandoned. When the quarry was eventually flooded by groundwater in the early 90's, it happened so quickly that everything was sort of frozen in place as it was at the moment right before the flood.

When you arrive at the lake, the topside jagged pyramids, called Rummu Ash-Hil, catch your eye. Limestone quarry cliffs that look like desert dunes, have sharp edges eroded by the wind and rain.

It’s a bit unnerving to see the old prison walls lined with barbed wire, and quite a contrast to the surrounding emerald and turquoise lagoon fringed with a lush forest. In the middle of it all are half-submerged ruins where the inmates once toiled away. Nature has totally taken over, and there’s this eerie juxtaposition of creepy decayed buildings jutting out of a vivid bluish-green lake.

There were only three of us diving that day, including myself and my dive guide, which upped the excitement and mystery. We descended into the cold water in dry suits. I followed closely behind as my guide, Rasmus, pointed out things to see and avoid—machinery, tires, lamp posts, old mining equipment, barbed wire, pots, wheelbarrows, and the barred windows from the prison cell. After spotting a lone beautiful flower on the bottom, at around 30 feet, I realized I was fooled when I swam up close and saw it was plastic. I don’t remember seeing any fish. And I certainly wasn’t expecting the underwater ‘zombie forest’-- a sunken woodland of live trees swaying in the gentle current. The branches were coated with thick algae that appeared to glow in the rays of sunlight filtering down. It was like a scene right out of Stranger Things.

I didn’t expect everything to be so preserved underwater. I had this vision of a tidal wave of water coming through an abandoned prison. But to see the remnants of it was truly surreal.

There's talk about turning this place into an adventure park. But the allure of Rummu, for me, is that it’s raw, abandoned, and a bit dark and dangerous beneath the surface. It belongs to nature now. We should let her keep it.

More Info: Rummu Adventurecenter