Record-low water levels in the Danube have exposed remnants of Europe's Nazi past, with dozens of second world war ships emerging from the riverbed during an intense drought. In the middle of the river on the Serbian and Romanian border, a broken-up hull was visible on a sandbank that is normally underwater. Other vessels were partly submerged, some still believed to be laden with weapons.

The ships were part of Adolf Hitler's Black Sea fleet that the German military deliberately sank towards the end of the war to slow down the Soviet advance. Historians say up to 200 German warships were scuttled in this way in September 1944. But Nazi Germany did not surrender until the following year in May 1945. So, in a move that perfectly encapsulates the strategic brilliance of the Third Reich, they sank their own ships to delay an inevitable defeat, and now those ships are popping back up like unwanted guests at a pool party.

The ships have been revealed during previous droughts only to disappear again as water levels rose along the second-longest river in Europe. The Serbian government has tried in the past to remove the wrecks, but most remain in place owing to the explosives they carried. Because nothing says 'let's clean up this river' like a bunch of unexploded ordnance.

Other second world war remnants have been found in other parts of the river, including a German military motorcycle in Budapest, Hungary. In Slovakia, police recovered an unexploded British 1,543lb (700kg) bomb. Police said authorities loaded it on to a 'specially modified firefighter vehicle with a sand bed, which ensured its safe transport' and took it to a 5-metre deep pit to detonate it. In 1944, Britain's Royal Air Force mined the river to disrupt enemy troops. So, both sides left their calling cards, and now the river is a historical theme park with a twist.

The Danube, which flows through 10 countries, has become increasingly difficult to navigate as low water levels create dangerous conditions. Prolonged droughts have left major European rivers at significantly lower water levels than is typical for the time of year, creating an energy crisis as many power plants rely on their natural water supply for cooling. Because when you're not dodging Nazi wrecks, you're worrying about whether your nuclear reactor has enough water to not melt down.

Intense summer heat and continuing drought conditions are being supercharged by the escalating human-caused climate crisis. Temperature records have been broken in several countries across central and eastern Europe as the extreme weather that has caused wildfires and droughts across the continent continues. Slovakia, Austria and Hungary registered record temperatures this week. On Thursday, the Slovakian hydrometeorological agency said a new national record of 42C (108F) had been reached in the village of Dolné Plachtince. So, while the past is literally resurfacing, the present is just getting hotter. Cheers.