Pene-exclave

A pene-exclave is a part of the territory of one country that can be conveniently approached—by traffic in particular—only through the territory of another country. Pene-exclaves are also called functional exclaves or practical exclaves. Many pene-exclaves partially border their own territorial waters (i.e., they are not surrounded by other nations' territorial waters), such as Point Roberts, Washington, and Minnesota's Northwest Angle (both in the United States). A pene-exclave can also exist entirely on land, such as when intervening mountains render a territory inaccessible from other parts of a country except through alien territory. A commonly cited example is the Kleinwalsertal, a valley part of Vorarlberg, Austria, that is accessible only from Germany to the north.