Next time you're drawing a border between countries along a river, make sure the riverbed isn't planning to shift. The Serbs and Croats didn't take this advice, and they're still arguing about who owns what land.

The roots of the problem go back to the 19th century. They recorded the current border in the land registry back then. And the Croats consider it the only correct one. The Serbs, on the other hand, say the border was drawn along the Danube at the time. So let's count it that way now too. But over 200 years, the riverbed has shifted noticeably, and Serbia now has 140 square kilometers more land.

In 2000, the countries created a special commission to settle the dispute. Over 10 years, it met all of 2 (two!) times and came to the conclusion that yes, they do have different understandings of the border. I'm not going to complain anymore about how long it takes to renew my residence permit.

In 2002, there was even a shooting incident when the mayor of the Croatian city of Vukovar and a group of activists decided to visit their lands by simply rowing a boat across the river. But the Serbian police detained everyone and then let them go.

And on a couple of islands between the countries, they even set up unrecognized micro-states — Liberland and Verdis. But it doesn't seem like you can just visit them. Plus, nobody actually lives there.