The Child fair does exactly what it says on the tin.

It wasn't supposed to be a town on its own like that, it was supposed to be IN a town or city but at the time I couldn't think up a decent name so I just placed it on the map as is.

Due to The Blight that the land is suffering, children have become worth their weight in gold. The states sell off any orphans to fund their war efforts, kidnapping and roaming armed bands hunting for children are commonplace - it's not a great time to be young.
The Child Fair is the biggest such place, where people bring their wares (including destitute fathers selling their own children) from far and wide to get the best prices. There are various smaller fairs and auctions throughout the lands, but the one in Rydony is the biggest.