Gibraltar isn't the world's weirdest border

Borders are fascinating places. The subtle changes in scenery and atmosphere as you near the limits of one territory and enter the orbit of the other; the way fencing gets higher and fiercer. Then there’s the shuffling of papers and passports, the opening of suitcases, car boots and, sometimes, wallets. The nervous sweat in no-man’s-land as men who reek of tobacco and bad coffee judge your suitability to enter or, worse, leave. In nearly all ways the (more or less) borderless new Europe is a wonderful thing, but something has been lost along the way.

If ordinary borders are weird, then the very special lines that surround the world’s several hundred anomalous enclaves and exclaves are museum pieces of geography, living testaments (as much as any castle or monument) to forgotten chapters of history. The current spat over Gibraltar, a pene-exclave of British territory which began with an antique treaty signed in a Dutch town, highlights the truth that when small, detached bits of one country abut or are surrounded by another, trouble often ensues.

For map nerds like me, the weird world of the enclave and exclave is as exciting as it gets. Discovering, at the age of nine, that there is a bit of Germany forever marooned in Switzerland (the city of Konstanz) was like finding a four-leaved clover. What must it be like, surrounded by another nation? What happened in the war? Did Nazi officials and soldiers have to take off their uniforms when bicycling through one to the other? Could they buy cuckoo clocks on the way? Look closely and you will see bits of Germany marooned in Belgium, slices of Italy stuck in the Swiss Alps, chunks of Spain cut off by Andorra and slivers of Finland stuck in Sweden.