Water levels have dropped in major rivers across Europe as the region suffers under a historic drought. In those dry riverbeds, centuries-old warning messages have emerged, locals report. The “horrifying” boulders are known as “Hungersteine,” or “Hunger Stones,” local German reporter Olaf Koens said in an Aug. 11 tweet. One of these stones is embedded in the Elbe River, which runs from the mountains of Czechia through Germany to the North Sea, POLITICO journalist Aitor Hernández-Morales tweeted the same day. The stone, dating back to a drought in 1616, is once again visible in the dry riverbed, Hernández-Morales said. The...