In my experience it's safe but only during the day and in public spaces with many people. Make sure they know where they are at all times and they have charged phones with data for GPS in case they get lost
My neices travel alone often and they would feel pretty safe. I think it also depends on their own comfort and confidence level. Do they travel alone often? Are they used to handling stressful or unsafe situations?
I've always wanted to visit an authentic Greek farmers market (this is a pic of the one I go to in Toronto, I love it!). Are there any good ones in downtown Athens? If so, where are they and do you have any tips?
I just moved to Athens a few months ago but I haven't been to any of the museums because of the pandemic but I'm planning on going this summer. Does anyone know if there are student discounts for museum tickets?