Toplitzsee

The Toplitzsee is small, about two kilometres by four hundred metres, hemmed in by cliffs and forest at the head of the Ausseerland, and it is meromictic: the water does not turn over, so below about twenty metres there is no oxygen at all, only a saline layer with bacteria and no fish, and objects sunk in it are preserved. That property is why the lake is famous. It was used as a naval testing site during the war, and in the closing weeks crates were rowed out and dumped; salvage since the 1950s has recovered counterfeit British banknotes from Operation Bernhard, the German scheme to wreck sterling, along with weapons and documents. Repeated expeditions since - and several deaths among divers - have produced very little more, though the treasure stories persist. The visit itself is a rowing boat across a very dark lake.

What you actually see

• A lake with a dead layer - no oxygen below twenty metres, no fish down there.
• Hand-rowed boats - the traditional plattenboote crossing the water.
• Cliffs and forest - the enclosed setting at the head of the valley.
• The Operation Bernhard story - counterfeit sterling recovered from the bottom.

When to go

May to October. Half a day.

Honest expectations

Access is on foot from Gössl and by boat only - no road to the lake. Swimming and private diving are restricted. Treasure stories are mostly that; the recovered material was banknotes and scrap.

Nearby

The Grundlsee and Kammersee are either side on the Three Lakes Tour.