Treaty of Maastricht (1843)
The Treaty of Maastricht, signed in 1843 by Belgium and the Netherlands four years after the Treaty of London established Belgian independence, finally settled the border between the two countries. == Border enclaves == Inability to decide a clear line of demarcation in Baarle-Hertog resulted in the division of the disputed territory into 5732 separate parcels of land.
Source: Wikipedia — Treaty of Maastricht (1843) (CC BY-SA 4.0)