I once walked down the stairs to the underground gents (now closed down, next to The Robert Peel statue in Bury) about thirty years ago and noticed two blokes stood next to each other at the urinals looking a bit dodgy.
It made me uneasy, so I walked out and thought I would go back in ten minutes when they had gone.
I walked down the steps again and they were still there fiddling about, so I did an about turn and left them to it :)
The toilets were closed down and sealed up shortly afterwards by the council, because apparently they had a notorious reputation.