West Berlin was an enclave located in the middle of the GDR, detatched from West Germany. This geological characteristic of the city lead to historical events such as the Berlin Airlift and the construction the Wall. This dilemma resolved when Germany was unified in 1990 and Berlin became one city, but there are numerous enclaves and exclaves scattered across the world.
Robinson, R. (2010) Enclaves of the World. [online] http://enclaves.webs.com/ [03/03/2010]
Krogh, J.S. (2010) Enclaves, Exclaves and the Likes. [online] http://geosite.jankrogh.com/ [03/03/2010]