Not because they are on some kind of vacation, or to study (though they are students), but because the magic can be used to protect them.
Protected not by the government, which, to be blunt, is being kind of useless and in denial. By another group, unofficial, or semi-official. And then I started to think about how this group can possibly control these sites, and why the government would let them.
It's not like they are the official Society of Wizards type. They're rather specialists. Our main character is going to find it a bit -- interesting because the magic he wants to study is not the magic they are in the habit of studying. And the government is not overly fond of them, though they aren't like another -- network, which really consists of scholars of magic that is at least a problem.
Hmmm. . . possible it's all privately owned. That this wizard and that one each managed to get title to this place and that location. . . .
I suspect I shall have to downplay the significance of the magic. Make the places something more useful to the specialists than to wizard in general.