Enclave and exclave
Territory (or part of one) entirely surrounded by the territory of one other state / From Wikipedia, the free encyclopedia
An enclave is a territory that is entirely surrounded by the territory of only one other state or entity. An enclave can be an independent territory or part of a larger one.[1] Enclaves may also exist within territorial waters.[2]: 60 Enclave is sometimes used improperly to denote a territory that is only partly surrounded by another state.[1] Enclaves that are not part of a larger territory are not exclaves, for example Vatican City and San Marino (both enclaved by Italy) and Lesotho (enclaved by South Africa) are enclaved sovereign states.
An exclave is a portion of a state or district geographically separated from the main part, by some surrounding alien territory.[3] Many exclaves are also enclaves, but not all: an exclave surrounded by the territory of more than one state is not an enclave.[4] The Azerbaijani exclave of Nakhchivan is an example of an exclave that is not an enclave, as it borders Armenia, Turkey and Iran.
Semi-enclaves and semi-exclaves are areas that, except for possessing an unsurrounded sea border (a coastline contiguous with international waters), would otherwise be enclaves or exclaves.[4]: 116 [5]: 12–14 Semi-enclaves and enclaves are mutually exclusive. Likewise, semi-exclaves and exclaves are mutually exclusive. Enclaves and semi-enclaves can exist as independent states (Monaco, The Gambia and Brunei are semi-enclaves), while exclaves and semi-exclaves proper always constitute just a part of a sovereign state (like the Kaliningrad Oblast).[4]
A pene-exclave is a part of the territory of one country that can be conveniently approached—in particular, by wheeled traffic—only through the territory of another country.[6]: 283 Pene-exclaves are also called functional exclaves or practical exclaves.[5]: 31 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. 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.