We have them in Slovenia. In the summer local castles will put on a fair for the tourists and kids. Sometimes multiple!
Typically you get a visiting troupe or two from Italy, they like to do flag twirling shows. There’s always a group of folks from Czech who put on an armored fighting competition. I’ve seen jousting tournaments too. And then you have a slew of local artisans selling wares roughly inspired by the time period. There’s often an outdoor play or two, maybe belly dancing.
It’s all great fun.