Debris left over from World War II is appearing all over Europe as the worst drought in decades causes rivers to dry up. In Croatia, the Danube has fallen from 50 feet to only 10 feet deep, revealing war relics from rifles and ammunition to entire tanks and armored personnel carriers. On some artifacts, Nazi insignia are still visible. In nearby Serbia, the twisted remains of Nazi warships blown up by retreating German troops are slowly emerging from the water. The river was wide and deep, said Russian military attaché Anatolij Calisev, and certainly holds many mysteries.