AN ENCLAVE is a political unit that is completely enclosed within a foreign territory. It is called an “exclave” from the perspective of the country that has sovereignty over it. An enclave can also exist on a subnational level when a subdivision has land outside its parent territory. The enclaves can be created for geological, historical, or political reasons. Enclave is a French word of the diplomatic language, which passed into the other languages; it comes from the Latin inclavatus, meaning “closed with the key.”

Some enclaves are small nations completely surrounded by another one, for example SAN MARINO and VATICAN CITY, exclaves of ITALY, and LESOTHO, exclave of SOUTH AFRICA. Some nations can be enclaved except for a small part of the coast, as in the cases of GAMBIA, BRUNEI, and MONACO. Some other territories cannot be reached from their nation except by international waters, or are enclosed in other countries except for a small coast fragment: This is the case of the Spanish towns of Ceuta and Melilla in the north of MOROCCO and of the British colony of GIBRALTAR in the south of SPAIN. True enclaves are the Belgian municipality of Barle-Nassau in the NETHERLANDS; Busingen in GERMANY (exclave of SWITZERLAND); Campione d'Italia in Switzerland (exclave of Italy); and the town of Llivia in Spain (exclave of FRANCE). Madha is a land of OMAN enclaved in the UNITED ARAB EMIRATES; INDIA has 106 exclaves in BANGLADESH and Bangladesh has 92 exclaves in India.

A lot of enclaves in history do not exist anymore. Until 1861, the Pontifical State had the exclave of Benevento in south Italy, and the Papal States also had the exclave of the Comtat Venaissin, the region around the city of Avignon, enclaved in France, from 1274 until 1791. HONG KONG, until 1997 administered by Great Britain, now is part of CHINA. There are territories that are not true enclaves, but are practically. Some practical enclaves are not geographically detached from their nation, but are more easily reached by entering another country because of their location. Some villages of ESTONIA, for example, can be reached only by a road passing inside Russian land.

The more frequent type is the subnational enclave. Administrative division of countries, often for historical reasons, can create small lands enclaved in another province, region, or municipality. In AUSTRALIA, the Australian Capital Territory is an enclave of New South Wales. In AUSTRIA, Vienna is an enclave of Lower Austria. In COLOMBIA, Bogota is an enclave of Cundinamarca.

Other examples include: In Belgium, the Brussels-Capital Region is an enclave of Flanders, and also the capital of Flanders. In Italy, a lot of municipalities have exclaves: Citta di Castello, in the region Umbria, has the exclave of Mount Ruperto enclaved in the territory of the Marche region.

Ethnic enclaves are communities of an ethnic group inside an area where other ethnic groups are the majority. The historic Jewish ghettos in Europe and the Native Americans reservations in the UNITED STATES are some examples.