[pell]

>For anybody unfamiliar with Europe, I just want to add that there aren't any checkpoints or border crossings, you just drive through or walk over. Half the time you won't even notice you're doing it. You're just supposed to have your ID on your person when you do.

The above is only true in the Schengen zone. As soon as you cross the border to a non-Schengen country or you arrive from a non-Schengen country you will go through normal border control (with some exceptions). This includes multiple EU countries beside Ireland like Romania, Bulgaria or Cyprus. And many non-EU countries like Bosnia, Serbia, Monaco, Kosovo, Andorra, Ukraine, Turkey, Russia, etc.

[usrusr]

But it also includes certain non-EU countries, like Switzerland. You won't notice having crossed the border before your phone notifies you that it just disabled data thanks to roaming charges getting capped at 50 without confirmation.

(I'm exaggerating, but only slightly.. the irony is that I used to have data roaming included in Switzerland, but the network forced me to a new plan that doesn't have that because the old one was almost but not quite complying with EU roaming rules)

[ajuc]

> As soon as you cross the border to a non-Schengen country or you arrive from a non-Schengen country you will go through normal border control (with some exceptions)

Nothing in EU is as simple, therefore it's not only a Schengen/non-Schengen thing. For example a border between North and "regular" Ireland isn't marked in any way, you just cross a brook or a field.

[messe]

> you just cross a brook or a field.

Or walk to the other side of the room. The border cuts through a number of houses and businesses as far as I'm aware.