Assuming from your profile that, like myself, you live in the Netherlands, I'm pretty sure you have no objections to our land borders... Of course, yo have to pay attention to actually notice those as you cross them.
My point is, those borders are still very real, they have great social, cultural, legal and economic significance, yet they don't serve any of those three purposes.
My point is, those borders are still very real, they have great social, cultural, legal and economic significance, yet they don't serve any of those three purposes.