One of the quietest horrors I've ever felt was this one weekend in Istanbul when I was walking home alone at 2am, down a very busy main street (Istiklal), and slowly realized that every single other person on the street was a man.
the feeling of searching through the crowd with increasing worry to find another female face and not seeing any was just one of the weirdest, most unsettling experiences of my life
turns out I was right to be worried, I got followed home and very nearly assaulted that night, saved only by my primal screams which turns out are super effective
The reason it was scary was because women weren't on the street for a reason. I was the only person of that group who didn't know the reason. I probably would be worried also if the same thing had happened with race.