The scourge of Allied bomber crews during World War II, the 88mm flak gun was the Third Reich's most dangerous and potent defensive weapon and the greatest threat to Allied airmen - perhaps an even greater threat thant he Luftwaffe's fighters. Allied ground forces didn't fare to well against this gun either, as it could be lowered to level position and used to kill tanks in one shot. Take at the Austrian Army Museum in Vienna.
Moving photo.