You probably think the only land border has is with US. Until about yesterday you would’ve been right. But after arguing with Denmark for years over the ownership of tiny Hans Island about halfway between Greenland and Canada, they have finally agreed to draw a line about a mile long through the island with Canada owning what is on the west side of the line and Denmark owning the other half. The island is uninhabited and probably worthless. Maybe sea level rise will obliterate it.
Please see this thread on same subject: