Baixa Cerdanya (literally "Lower Cerdanya") is sometimes just called Cerdanya, because Alta Cerdanya ("Upper Cerdanya") is part of France, not part of Spain.
Llívia, in Baixa Cerdanya, is a Spanish enclave, completely surrounded by French territory.
Official comarcal web site (http://www.cerdanya.org/)
IDESCAT: statistical information about Baixa Cerdanya (in Catalan) (http://www.idescat.es/servlet/BasicTerr?TC=3&V0=2&V1=15&PDF=FALSE&VOK=Confirmar)
Information about Baixa Cerdanya on the site of the Generalitat de Catalunya (in Catalan) (http://www.municat.net:8000/omunicat/owa/mun_p01.dad_ens?via=6&cod=8101540003)
BaixaCerdanya is a comarca (county) in northern Catalonia, in the Pyrenees, along the border of Catalonia with France and with the principality of Andorra.
BaixaCerdanya is the southern half of the historical territory of Cerdagne, divided by the Treaty of the Pyrenees (1659) between France and Spain (Catalonia).
BaixaCerdanya (literally "Lower Cerdagne") is sometimes just called Cerdanya because the other half of Cerdagne, French Cerdagne, which people in Catalonia call Alta Cerdanya ("High Cerdagne") is part of France, not part of Spain.