Once upon a time, European borders were uprooted once more. After Napoleontic times in this case. The Vienna Treaty left a tiny 3.5 km2 parcel of land between the United Kingdom of the Netherlands and Prussia unresolved.
Noone would have ever cared, if there had not been a productive zinc mine on this parcel. Moresnet as it was called, was left as a neutral stretch for the time being, and careful negotiations began.
The zinc mine, however, was exhausted before the issue was resolved. For a while, the international Esperanto movement had great plans with stateless neutral Moresnet.
After the first world war, there were more important things on people’s minds and Moresnet was assigned to Belgium.
Read more on wikipedia. Unfortunately, the small museum is down for moving.
The world’s second worst border mess is found in the southwestern part of the Netherlands. The small village Baarle is split between a Dutch part Baarle-Nassau and a Belgian part Baarle-Hertog.
Borders run criss cross through streets, houses and even bedrooms. To make things worse, there is not one Belgian enclave on Dutch territory, but there are 22 (yes: twenty two). And within some of the Belgian parts, there are even second-order Dutch enclaves. So there is a part of the Netherlands with a part of Belgium in the middle, in which we find again stretches of the Netherlands. Are you still following?
Not that both governments have not tried to resolve this unpractical situation. Territorial negotiations have been going on and off since the 14th century..
Baarle-Nassau/Baarle-Hertog is only surpassed by the Cooch Behar enclaves between India and Bangladesh.
Read more on wikipedia.