Free time activities for children and adolescents are offered by sports clubs, churches and youth organizations.
Offers in Nordrhein-Westfalen:
Free excursion tips for families: https://www.nrw-tourismus.de/kostenlose-ausflugstipps-familien
http://www.ruhr-guide.de/freizeit/natur-und-erholung/kostenlos-im-ruhrgebiet-beliebte-ausflugsziele/17630,0,0.html
https://www.nrw-tourismus.de/familientipps