How to remove automatically subscribed calendar for public holidays on my iPhone? As you can see in the screenshot below, somehow my iPhone subscribed to a calendar which is called "Deutsche Feiertage" (German public holidays).

How can I find out where this is coming from and how can I remove it (not just hide or disable notification)?



I am not hundert percent sure, but I think it is there since I upgraded my Mac to macOS 10.12. It was also there in the calendar app. There it was really easy to delete it. But I cannot find I way to get rid of it on my iPhone (using iPhone 6 Plus with iOS 10.2).
You can't delete the iOS holidays calendar, only hide it. It is a subscribed calendar but it's part of iOS.