Flak towers (Flaktürme) were eight complexes of large, above-ground, anti-aircraft gun blockhouse towers constructed by Nazi Germany in the cities of Berlin, Hamburg, and Vienna from 1940 onwards. The towers were used by the Luftwaffe to defend against Allied air raids against these cities during World War II. They also served as air-raid shelters for tens of thousands of local civilians.
In Vienna military authorities chose the Augarten as one of several places to erect massive buildings for anti-aircraft defence to protect the inner city from Allied bombing. During summer 1944 the construction of a 55 metre high tower with platforms for anti-aircraft guns and nearby also a 51 metre high control tower was begun but not finished. Their remains are still visible in the middle of the park. Moreover during the war hundreds of cubic metres of rubbish were dumped on the site whilst armoured vehicles criss-crossed the garden and - as it is supposed - common graves were dug for hundreds of war victims.
References:Redipuglia is the largest Italian Military Sacrarium. It rises up on the western front of the Monte Sei Busi, which, in the First World War was bitterly fought after because, although it was not very high, from its summit it allowed an ample range of access from the West to the first steps of the Karstic table area.
The monumental staircase on which the remains of one hundred thousand fallen soldiers are lined up and which has at its base the monolith of the Duke of Aosta, who was the commanding officer of the third Brigade, and gives an image of a military grouping in the field of a Great Unity with its Commanding Officer at the front. The mortal remains of 100,187 fallen soldiers lie here, 39,857 of them identified and 60,330 unknown.