About 40 km South West of Tallinn lies the Soviet-era Rummu prison. It sits adjacent to a quarry that used to be mined for limestone. Groundwater was pumped out of the quarry to allow for mining activities, which were mostly carried out by the local inmates.
When the prison was closed in 2012, the water pumps were shut down and the entire quarry quickly filled up. Luckily for scuba divers, this resulted in an incredibly well-preserved underwater museum which lies mostly undiscovered.
How to get to Rummu Prison
It’s actually very easy to get to. I took a bus from the Estonian capital and was dropped off just outside the site.
The first thing you’ll notice is the old prison wall and the abandoned viewing towers, now standing like concrete and iron skeletons rising above the barbed wire.
You have to follow the wall all the way to the end, walking on a mixture of white limestone and soil which seemed to stick to my trainers till well after I returned to the UK.
The quarry was far bigger than I imagined. The dive centre is just to the left where the owners have recently set up a container and deck to simplify getting in and out of the water.
Our diving team was composed of an Estonian, a Swiss, a French, a Spanish, a Swedish and myself – a British/Argentinian diver. We buddied up, prepared our kits and since we were all wearing 7 mm suits and it was 24 °C outside we hurried into the water.
A long fence guided us towards our first site, the ‘Zombie Forest’. This stretch is composed of underwater trees with branches covered in what I can only describe as a greenish take on the fake spider web used for Halloween decorations. You have to swim amongst the trees, a stern reminder of the importance of streamlining your kit.
The dive only gets more surreal from that point on – from stretches of grasslands to swimming around buildings and over brick walls, all while swapping what would be the usual aquatic life for lamps, bottles, wheelbarrows, ladders and other leftover equipment.
For me the ‘garage’ was one of the highlights. This was the place where prison vehicles were once housed and maintained. It’s clear the building was cleared out before the quarry flooded – even the doors were gone. You can see there are various rooms and that the top of the garage skims the surface of the water, and it did make me wonder whether any of the inmates ever considered their trucks would one day be replaced by scuba divers.
On the way back to deck you’ll visit the old Soviet bunker, a mysterious shelter with zero light composed of a narrow opening at one end and a vertical metal cylinder at the other. No one I asked seemed to know what the purpose of this building actually was so it’s certainly awaiting a curious diving visitor to unravel its past.
Back on the surface, Rasmus (our brilliant guide) shared his knowledge on local history – a mixture of Soviet secrecy and eerie prison tales – and took us all the way up to Ash Hill, where we let some nitrogen out and soaked in the stunning views.
Getting there: Unlike some information available online, there is parking and you can drive there. Otherwise, catch a bus from Tallinn for 3 euros (pay the driver with cash or use contactless directly). Please note there is more than one place called ‘Rummu’ in Estonia, so double check you’re headed for the right one.
Dive Centre: AdventureCentre (PADI 5 star resort – can provide all equipment and tanks)
Water temperature: ~ 21 °C (on a hot day in August!)
Max Lake Depth: 14 m (but you’re usually diving at around 5 -7 m)
Vis: ~15 m
Recommended suit: 7 mm wetsuit
Weights: A reminder you’ll be diving in fresh water. We also used steel tanks (as opposed to aluminium), meaning you might not need as much weight as you normally do with a thick wetsuit.
Find out more about Rummu Prison, and other underwater cities, on the blog here.
Mariana Salgueiro has been found diving or thinking about diving since 2007, and is always happy to help other divers!