German POW castle (7)
I believe the answer is:
colditz
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">german pow castle</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for colditz that I've seen before include "German wartime prison" , "German POW castle" , "Castle used as a POW camp for Allied officers, 1940-45" , "WW2 prison castle" , "Oflag IV-C" .)