[1] After the 1938 Anschluss which annexed Austria to Nazi Germany, Hitler ordered Döllersheim, Zwettl, Allentsteig, and several other smaller neighbouring villages to be evacuated in favour of a large military training area,[2] even though (or perhaps because) it contained the grave of his paternal grandmother, Maria.

According to testimony given during the Nuremberg Trials by Hans Frank, head of the Nazi General Government in Poland, Hitler feared further clarification of the unconfirmed rumour that his paternal grandfather was a Graz Jew named Leopold Frankenberger.

The real reason for the area's selection may lie in its relatively sparse population, poor soils and consequently low agricultural yields, lack of industry, and not least, from a military training point of view, its very severe winter weather conditions.

[1] In World War II the facility was home to the 392nd Infantry Division and the site of several prisoner-of-war camps including Stalag XVII-C and Oflag XVII-A (from June 1940) near the abandoned village of Edelbach.

Upon implementation of the 1945 German Instrument of Surrender and the Allied occupation of Austria, the training ground was seized by the Soviet Army and, despite raised claims for restitution, has remained a military exclusion zone (renamed Truppenübungsplatz Allentsteig) to this day, now operated by the Austrian Armed Forces.