''In German Schloss can mean "castle" or "lock." I just discovered that it's the same with the Polish word zamek - which I thought was an interesting and surprising coincidence.
Are there any other languages that have the same word for "castle" and "lock"?''
https://forum.wordreference.com/threads/castle-lock.3130217/
Schloss (see pic) https://en.wiktionary.org/wiki/Schloss
Schloss = castle or lock
Q wrote = Castle LOCK
Emphasis on LOCK = PRISON