The countries that border only one other country

Seventeen countries have a land border with exactly one other country. Three of them are completely surrounded by that neighbour, six share an island with it, and two pairs have nobody else: Ireland and the United Kingdom, Haiti and the Dominican Republic.

The count uses 195 countries, the 193 members of the United Nations plus Vatican City and Palestine. Only land borders count, and only those of a country’s main territory. A border reached through an overseas territory, such as Gibraltar or French Guiana, is left out. The last section covers what changes if you count those. Another 39 countries have no land border at all.

The 17 countries and their only neighbour

Enclaves: Lesotho, San Marino and Vatican City

These are the only three countries with no coast and only one neighbour, so that neighbour surrounds them on every side. Lesotho is by far the largest of the three, at about 30,000 km², inside South Africa. All of it lies above 1,400 metres, which gives it the highest lowest point of any country.

San Marino and Vatican City are both inside Italy, about 230 km apart. Vatican City covers 0.44 km², which makes it the smallest country in the world.

Surrounded on land: Gambia, Monaco and Brunei

Gambia follows the Gambia River inland from the Atlantic and is under 50 km wide at its widest point. Senegal wraps around it on the north, east and south. The two were joined as the Senegambia Confederation from 1982 to 1989.

Monaco is the same arrangement on a smaller scale: France on the land side, the Mediterranean on the other. At about 2 km² it is the second smallest country after Vatican City.

Brunei sits on the north coast of Borneo, inside the Malaysian state of Sarawak. It is in two parts, split by the Malaysian district of Limbang. Until the Temburong Bridge opened across Brunei Bay in 2020, driving from one half of Brunei to the other meant crossing Malaysia.

Shared islands

Six of the 17 share an island with their neighbour and have no other land border. On two of those islands the arrangement runs both ways. Ireland’s only neighbour is the United Kingdom and the UK’s only neighbour is Ireland, through Northern Ireland. Haiti and the Dominican Republic split Hispaniola, with the Dominican Republic on the larger eastern part. No other pair of countries has only each other.

The other two islands are shared with Indonesia, which also borders Malaysia on Borneo. Timor-Leste holds the eastern half of Timor plus Oecusse, an exclave on the north coast of the Indonesian western half. Papua New Guinea shares New Guinea, and most of the border is a straight line along the 141st meridian east, with one bend where it follows the Fly River.

One neighbour on the mainland

Portugal’s border with Spain is one of the oldest in Europe. Most of it was fixed by the Treaty of Alcañices in 1297 and has barely moved since. The main exception is Olivenza, which Spain took in 1801 and Portugal still does not recognise as Spanish.

Denmark’s only land border is with Germany, across the base of the Jutland peninsula. The line dates from 1920, when a vote in Schleswig returned the northern part of the region to Denmark.

Qatar is a peninsula whose single land border is with Saudi Arabia. From June 2017 to January 2021, during the blockade led by Saudi Arabia, that border was closed, which left Qatar with no open land route out of the country.

South Korea’s only land neighbour is North Korea, across the Demilitarized Zone set up by the 1953 armistice. The zone is about 4 km wide and closed to ordinary travel, so in practice South Korea is reached by sea or air.

Canada has the longest border between two countries anywhere: 8,891 km with the United States, counting the stretch with Alaska. The US has a second neighbour in Mexico, so the relationship only runs one way.

Borders that do not count here

Lists of this kind disagree because some countries have land borders through territories outside their main territory. Count those and three countries drop off the list:

• United Kingdom: Gibraltar borders Spain, and the Sovereign Base Areas of Akrotiri and Dhekelia border Cyprus.
• Canada and Denmark: in June 2022 the two agreed to split Hans Island, between Ellesmere Island and Greenland. That gave Canada a land border of about 1.3 km with Denmark, through Greenland. Count Greenland as part of Denmark and both countries have two neighbours.

That leaves 14. Two other cases look similar but go the other way. France borders Brazil and Suriname through French Guiana, and the Kingdom of the Netherlands meets France on Saint Martin in the Caribbean. Neither touches the list, since both already have several neighbours in Europe. Spain is different again: Ceuta and Melilla on the north African coast are part of Spain itself, not overseas territories, so Morocco counts as Spain’s neighbour under either rule.

Neighbours are one of the clues in Guess the Country, and Name Every Country asks for all 195 from memory.