Look: Ancient stones, World War Two relics found as waters fall due to Europe's drought

Weeks of baking drought across Europe have seen water levels in rivers and lakes fall to levels few can remember, exposing long-submerged treasures - and some unwanted hazards.

In Spain, suffering its worst drought in decades, archaeologists have been delighted by the emergence of a prehistoric stone circle dubbed the "Spanish Stonehenge" that is usually covered by the waters of a dam.

Officially known as the Dolmen of Guadalperal, the stone circle currently sits fully exposed in one corner of the Valdecanas reservoir, in the central province of Caceres, where authorities say the water level has dropped to 28% of capacity.

It was discovered by German archaeologist Hugo Obermaier in 1926, but the area was flooded in 1963 in a rural development project under Francisco Franco's dictatorship. Since then it has only become fully visible four times.

Memories of past droughts have also been rekindled in Germany by the reappearance of so-called "hunger stones" along the River Rhine. Many such stones have become visible along the banks of Germany's largest river in recent weeks.

Bearing dates and people's initials, their re-emergence is seen by some as a warning and reminder of the hardships people faced during former droughts. Dates visible on stones seen in Worms, south of Frankfurt, and Rheindorf, near Leverkusen, included 1947, 1959, 2003 and 2018.

Another of Europe's mighty rivers, the Danube, has fallen to one of its lowest levels in almost a century as a result of the drought, exposing the hulks of more than 20 German warships sunk during World War Two near Serbia's river port town of Prahovo.

• UK officially declares drought in several regions