Drachensberg was a castle in Germany, hundreds of miles from Berlin. It was owned by Heinrich Himmler and used by the Black Coven as their base. Doctor Felix Kriegslieter abducted Ace and took her to Drachensberg via transmat to lure the Seventh Doctor there. After Hermann Goering and his men attacked the castle and wiped out the Coven, the Doctor set the nuclear reactor located in the basement to overload, destroying the castle and the advanced technology contained in it. (PROSE: Timewyrm: Exodus)