The world’s strangest borders

Most borders are a line between two countries. A surprising number are not, and the exceptions are where the map stops being an abstraction.

The town in thirty pieces

Baarle-Hertog and Baarle-Nassau are one town on the Belgium–Netherlands border, divided into around thirty separate parcels. Belgian enclaves sit inside Dutch territory, and several Dutch counter-enclaves sit inside those.

The cause is medieval: a long series of land sales and swaps between the Lord of Breda and the Duke of Brabant from the twelfth century onward, never rationalised. The border is marked in the pavement with crosses and the house numbers carry small flags, because which country a building is in depends on where its front door sits.

The enclaves that were finally tidied up

Until 2015, the India–Bangladesh border contained 198 enclaves, including Dahala Khagrabari — an Indian parcel inside a Bangladeshi enclave inside Indian territory inside Bangladesh. It was the world's only third-order enclave.

Tens of thousands of people lived in these fragments, in many cases with poor access to the services of either state. A land-swap agreement in 2015 exchanged them and let residents choose their citizenship, ending what was probably the most tangled border arrangement on Earth.

Countries inside countries

Three states are completely surrounded by a single other country: Vatican City and San Marino, both inside Italy, and Lesotho, entirely inside South Africa.

Lesotho is the outlier of the three by a wide margin — about 30,000 square kilometres of mountains, and the only country in the world with all of its territory above 1,000 metres.

Places you cannot reach from home

Point Roberts, Washington, sits at the tip of a peninsula that extends south of the 49th parallel. It is American, has around a thousand residents, and can only be reached overland by driving through Canada. Children cross the border twice a day to get to school.

Llívia is a Spanish town of about 1,500 people inside France, left over from the Treaty of the Pyrenees in 1659, which transferred a list of villages to France and did not include Llívia, because it was classed as a town.

Campione d'Italia is Italian, surrounded by Switzerland, and used the Swiss franc for most of its modern history. Büsingen am Hochrhein is German, also surrounded by Switzerland, and is in the Swiss customs area.

Exclaves at national scale

Kaliningrad is Russian territory on the Baltic, separated from the rest of Russia by Lithuania and Poland. Nakhchivan is Azerbaijani, cut off from the rest of the country by Armenia — which is why Azerbaijan's border with Turkey exists at all. Cabinda, Angola's oil-producing province, is separated from Angola by DR Congo.

The Namibian Caprivi Strip is a different kind of oddity: a narrow finger of land reaching 450 kilometres east, drawn in 1890 to give German South West Africa access to the Zambezi. The access turned out to be useless, because the river is not navigable to the sea from there.

Afghanistan's Wakhan Corridor was drawn for a comparable reason and worked better: a buffer strip agreed so that the Russian and British empires would not share a border.

The land nobody claims

Bir Tawil is roughly 2,000 square kilometres of desert between Egypt and Sudan, and it is claimed by neither. The reason is a rare piece of border logic working in reverse: there are two competing boundary lines between the countries, and each state prefers the line that gives it the larger and more valuable Hala'ib Triangle nearby. Claiming Bir Tawil would mean endorsing the line that loses them the Triangle. So both decline, and Bir Tawil is one of the very few genuinely unclaimed pieces of habitable land on Earth.

Borders that are not lines

The Korean Demilitarized Zone is a strip about four kilometres wide and 250 long, one of the most heavily fortified places in the world and, because almost nobody has entered it in seventy years, an accidental nature reserve.

The Cyprus Green Line runs through the middle of Nicosia, the last divided capital in Europe. And the Nepal–China border runs directly over the summit of Everest, so the highest point on Earth is a border marker.

The border that moves every year

High in the Alps, the Italy–Switzerland border near the Matterhorn is defined by the watershed on the Theodul Glacier — the line dividing where meltwater flows. As the glacier has thinned, that line has shifted, and with it the border.

The movement is real enough to matter: a mountain refuge near the Testa Grigia has ended up straddling a boundary that was unambiguous when it was built, and the two countries have had to negotiate the position rather than simply survey it. It is a rare case of climate change redrawing a political map directly rather than through its consequences.

The two islands a day apart

Big Diomede is Russian and Little Diomede is American. They are about 3.8 kilometres apart in the Bering Strait, with the international date line between them. Standing on one you can see the other, roughly 21 hours away by the calendar.

If any of this makes you want to check where these places actually are, the map quiz is the fastest way to find out how much of the map you can place — and the landlocked countries guide covers the related question of who has no coastline at all.