Unlike flying, crossing national borders by car is a far more real experience. Even in the European Union, where much of the border security has been removed between countries, there is something much firmer about driving across the line between France and Spain than flying from one to the other.
What is it, then, that makes this section of land France, and the one here Spain? Mutual agreement? Some borders seem to be becoming more and more futile just as geopolitical turmoil increases evermore, while others become seemingly impossible and dangerous to cross. But the road will always call, the borders will always succumb to the willingness to explore the geography restricted by politics and human error.