The article analyses the formation of mental links between the population of East Prussia and the natural and cultural landscape of the said German province after World War I. By interpreting landscape as an imaginary space whose symbols may impact identity, the author analyzes several ways of nationalization of the East Prussian landscape. They include: studies of the homeland newly defined by the Versailles Peace Treaty at school and in daily life; popularization of tours for youth of the pre-promoted places of the province; organized care of wartime military cemeteries moderately integrated into the landscape; the construction of the Tannenberg memorial complex and giving meanings to it; and reconstruction of war-devastated cities and towns of East Prussia. The article demonstrates that the creation of meaningful links between the German population, the homeland (East Prussia), the elements of its natural and cultural landscape, and the Fatherland (Germany) formed a unique perception of the region which was primarily related to its meaning of a German outpost in the East.