I'm visiting my Dsis at a camp/caravan site (in the U.K.) and I was just coming out of the toilets (there's a communal toilet/shower block) when some boys starting shouting at me and calling things to get my attention. My default is to ignore any kind of shouting/catcalling, so I didn't respond. I also didn't initially realise they were talking/shouting at me as there were a lot of kids around. So because I didn't respond, they then started shouting insults at me. They looked about 12 at the oldest. I don't know which tents/caravans they were staying in but their parents could have been just metres away and it didn't bother them.
For context I am 28, though often pass for a lot younger (often about 18). I just found it really depressing.