A record drought in Europe this year has exposed over a dozen boulders along the Elbe River, that usually stays below the water line, in and near the northern Czech town of Decin near the German border. Some of these boulders are carved with ominous messages warning people of the hard times ahead.

These boulders are known as “hunger stones”, and they were used as historical markers to record water level of rivers around Central Europe during periods of extreme drought since at least the mediaeval age. In older times, drought always meant bad harvest, and bad harvest meant hunger. Low water level in rivers also meant river trade came to a standstill cutting off food supplies, increasing prices and worsening conditions in general.