o yeah there are many trailer parks in at least The Netherlands and Belgium. Can't imagine there aren't any in the rest of Europe.
In the people that live in Dutch trailer parks are considderd criminal and usually involved in criminal activities like growing weed, scamming people, illegal cash collectors etc... And they also don't pay tax mainly because the the government it to afraid to collect it. And they are pretty stupid to because they get busted in hiddencamera tv shows all the time
I will try to find some pictures as visual support