Create a group to go to any Dutch city by train

First search for the city (only for Amsterdam, Den Haag, Groningen or Maastricht you can read more here why is it enough to go almost anywhere in Holland) and date. If you find a facebook group in the comments then you can join there. If you dont find or it is already full then you should create a new facebook group with the name of the city and the date and leave it in comments.