Every country has boundaries. For island nations and the unique country-continent of Australia, that’s water. But other countries literally rub elbows with other nations. For most, there are many shared borders. But a select few have only one border.
Canada

Canada is one of three countries in North America and the only one that can claim a single border, and that’s with the United States. To the north is the Arctic Ocean, and its coasts are bounded by the Pacific and Atlantic Oceans. However, its entire southern border is shared with the U.S. along with a solid claim to four of the five Great Lakes. Eight of Canada’s 13 provinces touch one or more of 13 U.S. border states. The two nations share the distinguished title of having the longest international border. You might also be surprised to find that the Canada-U.S. border is the busiest border crossing in North America.
South Korea

South Korea sits on the Korean peninsula and shares its northern border with its former compatriot, North Korea. Once a unified and sovereign nation, the two countries have technically been at war since American and Soviet troops officially ended armed conflict in the region in 1953. South Korea’s northern border sits right on the 38th parallel, an artificial border created at the close of the conflict to create two separate nations.
While the 38th parallel sits within the Demilitarized Zone (the DMZ) they are not the same thing. The DMZ refers to a 150-mile stretch of land that runs along the 38th parallel with 1.2 miles of neutral, unfortified grounds on the north and south sides of the parallel. If you’re feeling brave, you can take guided tours to the DMZ, and legally take a few steps into hermit kingdom North Korea.
Lesotho

Some countries only have one border because they’re entirely surrounded by another country. While this is rare, there is one more nation that also has this feature. This is known as an enclave country. Lesotho is completely enclosed by South Africa and boasts a population of 2 million people. The nation first came to be in the early 1800s under its original name, Basutoland, under King Moshoeshoe I. Over the years, Basutoland fell under British and Dutch control before being returned to its native people in 1966 and renamed the Kingdom of Lesotho.
Vatican City

As we mentioned, only two countries in the world have the distinction of being an enclave country, and Vatican City is the other one. Its official title is Vatican City State, and it is the home of the Catholic Church. The history of the Catholic Church’s papal states and autonomous rule within Italy and greater Europe is a long and complex one. But to keep it simple, even though the Vatican has existed for centuries, it didn’t become a separate entity from Italy until 1929. The lands are under the control of the Holy See with the pope serving as its ruler. However, even though the Vatican City State is sovereign from Italy, you’ll be happy to know that you don’t need a special visa or even your passport to visit this famed religious state. As long as you can legally enter Italy, you can walk right into the Vatican.
Haiti/Dominican Republic

So we know that there are a few nations in the world with only one border, but sometimes these countries occupy the same general lands. A perfect example of this is the island of Hispaniola, which is home to Haiti and the Dominican Republic. If you remember your history lessons, Christopher Columbus mistook the island for India on his initial voyage in 1492. We’ll fast forward through the history lesson and say that the island was divided between the French and Spanish. The French created Saint-Domingue (now Haiti), and the Spanish created La Republica Dominicana or the Dominican Republic. During the island’s colonial days, relations between the two island states were strained, and to a degree, they still remain difficult today. However, both countries are popular tourist destinations for Americans and Europeans.
United Kingdom/Ireland

Another popular “one island, two nations” situation is in Europe, although this one is a bit of a technicality. When you think of the United Kingdom, your first thoughts are of London, Manchester, or other famed cities in England. But the United Kingdom is comprised of four countries: England, Northern Ireland, Scotland, and Wales. So, since Northern Ireland is part of the United Kingdom, the entire nation can claim a single border with the Republic of Ireland. Once again, this border is created by a complicated history.
Northern Ireland was created in 1921 after popular opinion—and the Government of Ireland Act of 1920—pushed for the northern portion of the island to remain with the United Kingdom. Northern Ireland was home to unionists and descendants of Britain. So, it’s understandable that they wanted to remain with their motherland. Today, both nations are also popular destinations with thriving tourism industries.