How about...A Funfair!!! It could be a place where there's all kinds of contests like drinking contests, pie eating contests, fist fighting, horse racing, gambling, ring tossing, dice poker etc. Would also be a place to meet all kinds of people, at first all friendly and helpful but their sordid secrets are slowly revealed and the cheerful atmosphere turns out to be just a facade for much more sinister events...or everything is ok until the peasants get drunk and attack the nonhumans with Geralt having to choose whether to interfere or not.