It was returned to its original representation purposes during the second half of the 20th century, and briefly became a business park for small information technology and internet companies in the early post-millennium years.
But on completion the complex was dismissed by Hitler on a visit in February 1940, and Speer subsequently adapted it to serve as the Luftwaffe headquarters during Operation Sea Lion, the invasion of Great Britain.
[3][better source needed] On 6 January 1945, a blockbuster bomb was jettisoned on Ziegenberg by a returning Allied bomber, damaging the church and several houses, killing four residents.
During several months of 1945, the castle (under code name Camp Dustbin, from June on)[4] was the Anglo-American interrogation center for Albert Speer and Hjalmar Schacht[5] as well as Wernher von Braun, Ferdinand Porsche, Anton Flettner, and other technical, financial and industrial leaders.
[6] Soon thereafter a British-American detention center, commonly referred to as Camp Dustbin, for high-ranking German non-military prisoners of war, was established in parts of the complex.
Focused on key industrialists, scientists and economists, among those interrogated here were Hjalmar Schacht, Wernher von Braun, Ferdinand Porsche, and the leaders of the IG Farben chemical conglomerate.
The highest-ranking of these persons of interest was Albert Speer, the minister for armaments and wartime production who was detained in one of the buildings which he had redesigned as Hitler's chief architect a few years earlier.
It was later followed by the 5th U.S. Army Corps which operated an NCO academy, and by U.S. intelligence units which directed large parts of its espionage network in communist East Germany from here.
The costs of operating and maintaining the castle forced Brandis to sell her real estate to Klaus Landefeld, an information technology entrepreneur, in 2000.
At the end of 2012, Kransberg Castle was sold to a Turkish investor group led by entrepreneur Sebahattin Özkan, with plans to use it as an educational institution.
The castle serves as a wedding location with a registry office, and prior to the COVID-19 Pandemic the owner organised classical music concerts with internationally-known artists, which are planned to resume in the future.