Rummu Quarry

Rummu was a limestone quarry worked by prisoners from the adjacent Soviet-era prison. When the pumps were switched off after 1991 the groundwater came back and filled the pit, drowning the workings where they stood. What is left is a lake of startling turquoise with machinery, roads and buildings still underwater, and a bright white mountain of quarry spoil on the bank.

What you actually see

Water that reads pale green over the shallow ledges and deep blue in the pit, with the tops of submerged structures breaking the surface in places. Divers go down to the sunken buildings, and from the shore you can see straight down several metres on a calm day.

Beside the lake stands the spoil heap - a pale grey-white hill of crushed limestone, high enough to give a full view over the quarry, the water and the flat country beyond. The old prison buildings sit at the edge of the site.

When to go

• June to August - the water is at its most vivid and the site is fully open.
• May and September - fewer people, water too cold for most.
• Winter - the contrast between the white heap and the ice is striking, but the site may be closed.

Honest expectations

This is now a managed and ticketed recreation area with wakeboarding, diving and a beach - it is no longer the abandoned ruin that made the early photographs. Anyone expecting free access to an empty industrial site will find a gate and a price list.

The water is deep, cold and full of submerged hazards. Swimming outside the marked area and climbing on the ruins have both caused serious accidents here.

Nearby

Keila-Joa waterfall and the manor park are about half an hour north. Tallinn is under an hour east.