Beethoven, I can assure you there is NO glory hole in Amarin Plaza.
(That is technically impossible. Unless you have Mr. Swiss Pneumatic drill to cut a hole through a 10 cm thick concrete wall.)
Same for Sogo - I haven't seen any. And I really search for glory holes. Everywhere.

I know that Amarin can be dangerous. I got pickpocketed there. I haven't seen any unusual activiy of guards though. But I do believe that caution is required.
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I don't know for sure, but someone is cutting a hole in the restroom at the cinema of the Emporium. not [yet] open, though.