Don't worry MinimalistMommi, you're not the only one!
It's great to be able to let the children run loose there and it feels so safe as it is mainly families camping. I think the problem for us was that it can get dark very, very quickly so that if they've strayed a bit too far it can be quite disorientating.
We had a frantic search for our 7 year old there last year - took us about 1/2 hour to find him which doesn't sound long but when you're worrying it feels like infinity, don't want to imagine how this poor family felt through the night.
My OH found him sitting in a circle round a campfire with about twenty women who were celebrating a 40th Birthday - he said he wanted to go back the next night as then they were having cake!
i guess one thing is to make sure the kids have a torch, those ones with a whistle look like a good idea but they tend to drive you mad blowing them all the time. Perhaps a head torch if they are still playing at dusk so that they have a better chance of getting back to the tent and you can find them more easily if they don't.