NS-Ordensburgen

In Nazi Germany, the NS-"Ordensburgen ("National Socialist Order Castles", singular "Ordensburg"), also called Schulungsburgen", were schools developed for elite Nazi military echelons. There were strict requirements for admission to the schools. Junker candidates had to be aged between 25 and 30 years old, belong to either the Nazi Party, the Hitler Youth, the Sturmabteilung, or the Schutzstaffel, be physically completely healthy, and be pure-blooded with no hereditary defects. The term "Ordensburg" was borrowed by the Nazis from the historic Teutonic Order.
Under the reforms of the National Socialist Party, special schools for the children of important Nazi leaders were established. “Adolf Hitler Schools” were established for the elementary grades, and Ordensburgen were established for post-secondary school students. These schools were supposed to turn out future Party elite leaders, trained in both technical subjects and Nazi ideology. Ordensburgen were designed for students who had completed the Adolf Hitler Schools, undergone six months of compulsory labor-service training, two years in the army, and who had already chosen their profession.
Because the students were so isolated and their education was so specialized, they were often perceived as arrogant while knowing little of practical value. Many high-ranking Nazi officials chose not to send their children to these schools. Even Martin Bormann sent only one of his more troublesome sons to an Adolf Hitler School, as a form of punishment. 
The schools themselves were typically stark, modern structures with extensive facilities. Vogelsang, for instance, reportedly contained the world's largest gymnasium at the time. Each student was supposed to attend all four institutions in sequence, finishing at the historic site of the Medieval Marienburg for training that included live-fire military exercises.
The three institutions for education of political leaders and their educational focuses that were built were:
focus: "racial philosophy of the new order"
focus: "administrative and military tasks and diplomacy". This facility was used by Germany's Bundeswehr until the end of 2007.
focus: "development of character"
According to the training model, students were to spend one year at each castle in order to become familiar with each educational focus. The fourth and final "Ordensburg", planned for the site of the historic Marienburg Castle in West Prussia, was never built.