A Belgian-Dutch border town has enclaves inside enclaves inside enclaves

Baarle-Hertog, Belgian territory, is made up of about two dozen separate parcels scattered inside the Dutch town of Baarle-Nassau, the legacy of medieval land deals between local lords. Stranger still, several pockets of Dutch territory sit fully inside the largest Belgian parcels, forming counter-enclaves so rare that only one other example exists anywhere in the world.

— Standard geographic accounts, Baarle-Hertog — Boundary settled under the Treaty of Maastricht, 1843