C is A's enclave and is B's exclave.
In human geography, an enclave is a piece of land which is totally enclosed within a foreign territory. If another country has sovereignty over it, it may also be called an exclave:
- it is an enclave of the foreign territory which surrounds it
- it is an exclave of the country which has sovereignty over it
Exclave may also exist in subnational level when a subdivision exists outside of its parent division. (See #Subnational examples
The word 'enclave' crept into the jargon of diplomacy rather late in English, in 1868, coming from French, the lingua franca of diplomacy, with a sense inherited from late Latin inclavatus meaning 'shut in, locked up" (with a key, late Latin clavis). The 'exclave' is a logical extension created three decades later.
Some enclaves are countries in their own rights, and therefore not exclaves. Examples of these include:
A coastal territory cannot correctly be called enclaves, since the sea is not a foreign territory, hence disqualifying it of the "enclosed on all sides by foreign territory" criteria.
Countries that border just one country and the sea:
List of enclaves
- West Berlin (prior to the unification of Germany)
- Baarle-Hertog, a Belgian exclave in the Netherlands.
- Büsingen, German exclave in the canton of Schaffhausen, Switzerland
- Campione, Italian exclave in the canton of Ticino, Switzerland
- Llivia, Spanish exclave in France.
- Ormidhia and Xylotimbou in Cyprus, surrounded by the British Sovereign Base Area of Dhekelia
- Nahwa, an Omani enclave within Madha, which in turn is an exclave of the United Arab Emirates in Oman
- The most embodied enclave in the world is an Indian exclave called Dahala Khagrabari, which is embodied in a Bangladeshi enclave called Upanchowki Bhajni, which in turn is an enclave to the Indian exclave Balapara Khagrabari which in turn is an enclave to Bangladesh.
See also: List of international enclaves, and "Countries consisting of two non-contiguous parts" in the Country article.