Throughout the summer, unusually hot and dry weather in Europe has revealed a slew of archaeological treasures, from a prehistoric henge in Ireland, to an ornate 17th century garden in England, to a lost German village once submerged underwater. The most recent relic to surface amid the drought is a stark reminder that Europeans have long been afflicted by parched, damaging conditions. As the Associated Press reports, “hunger stones” warning of drought-induced hardships have started surfacing in the Czech Republic.

More than a dozen of the stones have been found in and near the town of Decin, which is crossed by the Elbe River. Due to scorching temperatures, the water in the river has dropped, revealing boulders that were once used to record low water levels. The rocks are etched with dates, and the earliest one currently visible is 1616.

But hunger stones did more than simply document drought: They also lamented difficult conditions and let people know that trouble was afoot. One of the rocks, for instance, “expressed that drought had brought a bad harvest, lack of food, high prices and hunger for poor people,” according to a 2013 study of drought in Czech lands. A German inscription on the same rock reads: “When you see me, weep.”

This particular hunger stone has become a well-known tourist attraction in the Czech Republic, according to NPR’s Camila Domonoske. It is among the oldest hydrological landmarks in Central Europe and, due to a dam that was built on a tributary of the Elbe in 1926, the rock can be seen approximately 126 days each year. But the low water levels in the Elbe today are nevertheless “exceptional,” Domonoske writes. Earlier this month, the Local reported that the river had reached its lowest levels in more than half a century.

The hunger stones are not the first sunken relics to resurface in the Elbe this summer. Earlier this month, receding waters exposed unexploded bombs that may have been dumped in the Elbe after WWII.

Scientists are particularly concerned about the current European heatwave because its increased intensity has been linked to climate change. But as the hunger stones suggest, the continent has seen its fair share of damaging droughts. A recent study, in fact, found that while 21st century droughts are “the most extreme droughts driven by precipitation deficits during the vegetation period,” they have not been as long or as severe as some of the historic droughts that have struck Europe over the past 250 years.

It is perhaps little wonder, then, that the Czech hunger stones bear ominous messages of impending troubles.