Canada and the United States share the world's longest international land border.
Spain and Morocco are separated by the Strait of Gibraltar, only about 14 km (9 miles) at the narrowest point.
Turkey is a transcontinental country, with territory in both Europe (Thrace) and Asia (Anatolia).
France has land borders with eight countries in Europe (including a small border with Brazil via French Guiana in South America).
The Himalayas form a major natural barrier between the Tibetan Plateau and the Indian subcontinent.
The Ural Mountains are traditionally considered part of the boundary between Europe and Asia.
The Pyrenees form much of the natural border between Spain and France.
The Alps influence borders and travel routes across several European countries.
Chile is one of the world's longest north–south countries and is narrow compared to its length.
South Africa completely surrounds the independent country of Lesotho.
The border between North and South Korea is one of the most heavily militarized borders in the world.
The Berlin Wall divided East and West Berlin from 1961 to 1989 during the Cold War.
The 49th parallel north forms much of the border between the United States and Canada.
Enclaves are territories completely surrounded by another country's territory.
Exclaves are parts of a country separated from the main territory by another country.
The Durand Line is the border between Afghanistan and Pakistan, established in 1893.
Maritime borders extend into oceans and are often based on distance from coastlines.
The Schengen Area in Europe allows passport-free travel across many European countries.
Disputed borders are areas where two or more countries claim the same territory.
Natural borders often follow geographic features like rivers, mountain ranges, or coastlines.