Quick bitch.
I googled "Avondvierdaagse" and the Wikipedia article is in Dutch and I can't figure out the word on the left to get it to translate it to English.
I think it's something that involves a lot of people walking?
I see you found the answer already.
Yes, lots and lots of people walking. It was obligatory, when I was in primary school. For my kids it is not, but, the oldest wanted to participate till grade 7, and the youngest will participate in grade 8 too, she just wants to have 8 medals, I think.
Parents are booked in to walk at least one evening too, as supervisors of the group. I hate walking in groups. But, at least this will be the last year that I have to do that. There is comfort in that. Kids from age 9/10 on are supposed to do the 10 km walk.
Worst of all days is the last day, when kids will be welcomed back with a band and lots and lots and lots of people. There will be an honoury walk through the village, and there is no escape possible. Since I always was the only one welcoming my kids, there is no escaping that night for me. Some kids are welcomed by their whole extended family, handing the kids presents, flowers and loads of candy. Can't not be there on that evening.
My evening where I have to do my walk will be Tuesday evening. Don't know if that is a bit more or a bit less than 10 km. Coincidence has it that I will be cycling with the same group during that day. So, at the end of the day, we'll probably be mutually fed up with each other.