It seemed to me that I would have written an article about the shortest international border a long time ago although it appeared I’d overlooked it. Let’s rectify that oversight.
The omission actually provided a benefit. Just about every one of these places was already featured in a previous Twelve Mile Circle article in a different context. That allowed me to combine a new article with a collection of "greatest hits."
I’ll start with a small number of caveats and clarifications. First, I’ll focus on truly international borders between independent and sovereign states. That eliminated very short borders between the People’s Republic of China and Macau and Hong Kong, for example. I also decided to duck controversies so don’t expect coverage of another brief boundary, the one between Egypt and the Gaza Strip. Finally I wanted to examine land borders specifically although narrow water boundaries such as the width of a river was acceptable.
Every border examined stretched less than 20 kilometres according to Wikipedia’s List of countries and territories by land borders
What was the shortest border? That’s not an easy question; it could be a toss-up.
SOURCE: flickr by By Ruth Flickr via Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic (CC BY-NC-SA 2.0) license
Crossing the World’s Shortest Border
The honor may go to the border between Botswana and Zambia which at most stretches 150 metres, and is the pivotal location that may come closest to being an international quadripoint when combined with Namibia and Zimbabwe (map). I featured this unusual configuration in the context of Namibia’s Caprivi Strip quite awhile ago in an article called "What Happened to the Handle?" A visitor can actually cross this tiniest of borders on the Kazungula Ferry.
The other contender may be found between India an Sri Lanka. There are various claims that one of the shoals that forms Rama Setu (Adam’s Bridge) may actually fall along the boundary between the two nations (map). That would put a land border at 100-ish metres in length if it actually exists. That’s why I tend to discount the claimant, though. It’s not a particularly feasible place to walk across assuming it’s even real.
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The land border between Spain and the United Kingdom at Gibraltar would probably be the most convenient option for the majority of the audience although it’s considerably longer than the first two instances. It stretches about ten times farther, at 1.2 km. Gibraltar earned a previous 12MC nod because a public road crossed directly over an active runway at the local airport. Street View now provides decent coverage of said road and it’s pretty memorable.
Europe made it onto the list multiple times because of a plethora of small states. The boundary between Italy and Vatican City came next, at 3.2 km. I didn’t want to dwell too much on Vatican City because it’s a frequent outlier and has been featured several times previously including in National Capitals Closest Together. I’ll mention a 2009 comment from the ever-loyal "Greg," who still reads 12MC all these years lager and continues to comment on articles. I was trying to generate 12MC hits from various places not yet represented at the time and Greg said,
Matter of fact, a friend of mine was recently at the Vatican visiting a family member, and I know he visited your site while he was there, because he emailed me about your post on the Wakhan Salient, which was published at the time. Maybe his internet, however it was set up, went through a .it ISP?
Sadly I still haven’t recorded a Vatican hit so I think there may be some merit to his Italian-based Internet Service Provider theory.
The 4.4 km border between France and Monaco followed. I focused on Monaco in Almost Landlocked and I don’t really have any more to add. Monaco is another one of those places that comes-up frequently in geo-oddity trivia.
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Then came the 9 km boundary between Turkey and Azerbaijan. Turkey has an odd dangling appendage that’s nearly snipped-off between Iran, Armenia and the Nakhchivan Autonomous Republic exclave of Azerbaijan. This area of tightly packed international neighbors was featured in Fictional Geo-Marathons.
Of course I can’t forget the border between France and the Netherlands. It doesn’t occur in Europe, rather it happens on the Caribbean island that they share between them, Saint Martin / Sint Maarten. I was fortunate enough to explore this 10.2 km frontier extensively in person a couple of years ago and reported my finding to the 12MC community in Saint Martin Borders and Boundaries
The final two spots to round-out the international borders of less than 20 km are Morocco and Spain at 17 km, via various Spanish outposts such as Ceuta, Melilla, and Peñón de Vélez de la Gomera; and the 19km border between North Korea and Russia.