Discussion: Do we have a civic duty?

We are all familiar with the concept of "civic duty". We learn the term at a young age. Our goal in this meetup is to investigate the notion of civic duty and the strong sentiment(s) implied by it.

Here are just a few motivating questions to keep in mind:
Do citizens necessarily have a civic duty?
If so, what is that duty?
If not, is there a cost in disregarding the idea?