List of countries that border only one other country
This is the list of countries that border only one other country, with only land borders being counted. Some of these countries have several neighbours "across the sea". As an example Denmark "borders" Sweden and Norway by sea, and Canada has sea boundaries with Denmark (between Baffin Island and Greenland) and France (between the island of Newfoundland and the territory of St. Pierre and Miquelon). Other countries may border only one other country by sea, such as Sri Lanka.
Territory leased or ceded by one country to another for perpetual use, but not in sovereignty, such as Guantanamo Bay Naval Base in Cuba, or memorials, such as the American Cemetery in France, do not constitute true territorial borders, because the land occupied remains a formal part of the host country.
Countries bordering only one other country
|Country||Neighbour||Border length (km)||Notes|
|Brunei||Malaysia||381||Borders the Malaysian state of Sarawak on the island of Borneo.|
|Canada||United States||8,893||The border around the area of Hans Island between Canada and Greenland (a constituent country of the Kingdom of Denmark) is disputed and undefined. Canada also shares a small maritime border with the French overseas collectivity of Saint Pierre and Miquelon.|
|Cyprus||Akrotiri and Dhekelia (UK)||The island of Cyprus is de jure divided between the Republic of Cyprus and the British overseas territory of Akrotiri and Dhekelia. De facto, however, the northern third of the island is controlled by the Turkish Republic of Northern Cyprus, separated from the Republic of Cyprus by a United Nations buffer zone.|
|Denmark||Germany||68||Denmark is connected to Sweden via the Øresund Bridge.|
|Dominican Republic||Haiti||360||On the island of Hispaniola.|
|The Gambia||Senegal||740||The Republic of the Gambia is bordered north, south and east by Senegal.|
|Haiti||Dominican Republic||360||On the island of Hispaniola.|
|Ireland||United Kingdom||360||The Republic of Ireland borders Northern Ireland, a constituent country of the United Kingdom, on the island of Ireland.|
|Lesotho||South Africa||909||Lesotho is an enclave which is entirely surrounded by South Africa.|
|Papua New Guinea||Indonesia||820||On the island of New Guinea.|
|Qatar||Saudi Arabia||60||The planned Qatar–Bahrain Friendship Bridge would connect Qatar to Bahrain.|
|San Marino||Italy||39||San Marino is an enclave entirely surrounded by Italy.|
|South Korea||North Korea||238||On the Korean Peninsula, at the Demarcation Line. The two countries are separated by a 4 km wide Demilitarized Zone.|
|Timor-Leste||Indonesia||228||On the island of Timor.|
|United Kingdom||Ireland||360||On the island of Ireland. The British Overseas Territories of Gibraltar and Akrotiri and Dhekelia border Spain and Cyprus respectively, but these territories are not part of the United Kingdom proper (see #Dependent territories section).|
|Vatican City||Italy||3.2||The Vatican is an enclave entirely surrounded by Italy.|
Causeways, bridges, and tunnels
Borders relevant to this list may arguably include short theoretical borders in the middle of man-made constructions. Also, artificial islands or causeways could be disputed.
- Denmark: in addition to its border with Germany, technically also has an extremely short border with Sweden across the Øresund Bridge.
- Singapore: although an island nation with no natural land borders, is connected to Malaysia by the Johor Causeway and the Malaysia-Singapore Second Link.
- Bahrain: likewise an island nation, is connected to Saudi Arabia by the King Fahd Causeway; the Qatar–Bahrain Friendship Bridge connecting it to Qatar is planned but as yet incomplete.
- United Kingdom: in addition to its border with Ireland, has a border with France in the Channel Tunnel.
In some cases, a dependent territory of one nation borders another nation.
- Greenland: a constituent country of the Kingdom of Denmark, has a border dispute with Canada around the area of Hans Island. [clarify][dubious ]
- Akrotiri and Dhekelia: British sovereign base areas, border the Republic of Cyprus. Dhekelia also borders the Turkish Republic of Northern Cyprus, but the latter is recognised only by Turkey.
- Gibraltar: a British overseas territory, occupies a small peninsula and has a 1.2 km land border with Spain.
- Hong Kong: comprising a continental portion and more than 200 islands in the South China Sea, was formerly ceded and leased by Qing China to the United Kingdom. It was returned to the People's Republic of China in 1997, but has since then operated with its own judicial system under the policy of "One Country, Two Systems". The land border and coastline, although no longer one between two states, are still controlled as though Hong Kong were an international exclave.
- Macau: comprises a peninsula and two islands in the South China Sea, 60 km west of Hong Kong, and like Hong Kong was formerly administered by a colonial power (in this case, Portugal) but returned to the People's Republic of China in 1999. It too has its own judicial system and retains border and coastal controls similar to those of an exclave.
- /: The island of Saint Martin is split between two island territories: the northern half, Saint-Martin, is a French overseas collectivity; the southern half, Sint Maarten, is one of the four constituent countries that form the Kingdom of the Netherlands.
There were many countries that historically had only one neighbour. Some no longer exist while others now have either no land borders or borders with more than one nation due to border changes.
- Korea bordered only China for several hundred years before 1860, after which a second international border with Russia appeared (approx. 17 km long), according to the Convention of Peking.
- Ciskei, one of the South African "independent" homelands, reincorporated on April 27, 1994.
- Venda, one of the South African "independent" homelands, was a true enclave bordering only South Africa and separated narrowly from Zimbabwe by the Madimbo corridor to the north; reincorporated on April 27, 1994.
- Dominion of Newfoundland, with Canada, until March 31, 1949 when it became the Canadian province of Newfoundland (now named Newfoundland and Labrador).
- The Kingdom of Scotland and the Kingdom of England bordered each other until 1707 when Scotland and England were united by the Acts of Union, see Anglo-Scottish border.
- Japan bordered Russia on the island of Sakhalin from 1905 until 1910, when a second border with Manchuria (China) and the Russian Far East appeared upon Japan's annexation of Korea. Both Sakhalin and Korea were relinquished in 1945. (See Karafuto Prefecture and Empire of Japan).
- Weihaiwei, 1898-1930, British colony on a leased territory from Manchu Ch'ing Empire. Transferred to the Republic of China in 1930.
- The Colony of Tasmania bordered only by the Colony of Victoria (on Boundary Islet), until the creation of the commonwealth of Australia.
- Enclave and exclave
- Island country
- Land borders
- Landlocked country
- List of countries and territories by land and maritime borders
- List of enclaves and exclaves
- List of island countries
- List of divided islands
- List of political and geographic borders
- List of sets of four countries that border one another