South American tour groups comprised of 15 year old girls. The groups normally range in size from 20-60+. They'll walk through the parks
chanting quite loudly, sometimes
walking arm in arm and just
behaving as you'd expect a large pack of teenage girls to do. I think it's awesome that they get to go on such a trip, and individually I'm sure they're mostly very sweet girls (we've seen examples of it). However in a group they can be a bit
annoying. Nothing to be "scared" of, just something to note. You don't want to be stuck in a long standby line with them.
I've heard they trash the value resorts, but we stay offsite so I've never seen that side of it.