With the official app of the city of Castrop-Rauxel, you can also access information and services from your city while you are out and about. What the CAS app can do: Current What is happening in Castrop-Rauxel? What's new? With the CAS app you are always up to date. Information from the city area, events and daily press releases can be found here at a glance. Idea and deficiency reporter For example, have you discovered a pothole or an idea that you would like to convey to the city administr