In the interwar years, Bitburg, like most of the Eifel region, was impoverished and comparatively backward. Economic growth began after the Nazi Seizure of Power and the Nazi regime's introduction of employment-boosting public works projects, including infrastructure for war, particularly the Westwall; new armed forces barracks; and the development of the Kyll Valley railway. It is said that the building now used as the post office at Bitburg Annex (what is left of Bitburg Air Base) was the headquarters for Adolf Hitler when he was in the city.