The Klein Glienicke Family Tunnel

Klein Glienicke was a part of Potsdam almost completely surrounded by West Berlin territory. Two families living there waited a long time for a heatwave: under normal conditions the high groundwater level would have made tunnelling impossible, and for that reason the GDR considered the area not at risk from tunnels.

Using only a child's shovel and a spade without a handle, they dug a 19-metre tunnel from the cellar of their house under the Wall. The spoil was moved on a small wooden cart and piled up in the cellar. The exit lay just 80 centimetres beyond the Wall on West Berlin ground.

On the night of 25–26 July 1973 two brothers, their wives and five children aged 7 to 14 escaped. A close relative had informed the Stasi of their plans, but by the time the Stasi decided to arrest them, they were already at the Marienfelde refugee reception centre. The day after the escape, border soldiers sealed the exit with a wall 70 centimetres thick and filled the tunnel.