Border squabbling in the Balkans has caused untold trouble over the centuries, but the former Yugoslav republics of Croatia and Slovenia have never actually been to war. That doesn't mean they like each other, though. What happens when you try to run a nice tavern that happens to sit smack on the border?

This inn is in two countries.

When Yugoslavia broke up in 1991, the new border between the two countries followed a tiny stream that divided the Slovenian town of Obrezje from the Croatian town of Bregana. A rustic local inn, Kalin, stood right on the border. Owner Sasha Kalin is, appropriately enough, the son of a Slovenian man and a Croatian woman, and he's painted a bright green line on the floor next to the pool table to show customers where an international border slices the tavern in half. The restaurant sits on Slovenian soil, but you'll be entering Croatia if you want to play billiards or use the restroom.

A watering hole with armed guards from two nations right outside.

Outside Kalin, a line of cement planters marking the international border has turned the street into a dead end. If you make a wrong turn heading home, Croatian police will emerge from their guardhouse to "secure the border." The border guards on both sides can smell the delicious roast pork and venison being served inside, but never grab a meal there. If they walked on the wrong side of the pool table, they could cause an international incident.

Sitting on an international border can be bad for business.

Running a multi-national pub in the middle of nowhere can be tricky. Kalin pays taxes only in Slovenia, but has a separate phone number in each country. He doesn't get so many Croatian guests now that they have to show a passport just to get to his front door, so he only stocks Slovene beers. An old photo in the hallway shows Kalin's mom's dog in happier times, peeing on the border marker right outside the tavern door.

Kalin Tavern is just one skirmish in a bigger conflict.

The two nations disagree over many points of their border, especially where it hits the Adriatic at the Gulf of Piran. Croatia's version of the borderline would prevent Slovenia from accessing international waters; in retaliation, Slovenia has worked to block Croatia's entrance to both the European Union and NATO. Last month, an EU arbitration court granted Slovenia a corridor to international waters, but Croatia has said it will refuse to observe the ruling. Sasha Kalin is just looking forward to the day when Croatia joins the passport-free zone of the Schengen Area. Then the concrete flowerpots outside his front door will disappear, and his heavily guarded dead-end street will just be another road through the village.

Explore the world's oddities every week with Ken Jennings, and check out his book Maphead for more geography trivia.