Comarcas of the Basque Country

The autonomous community of the Basque Country within Spain contains several comarcas or eskualdeak in the Basque language, referring to local districts, grouped into its three long-established provinces.
The Basque Government's statistics department Eustat has divided the districts using a 20-comarca model in its reports relating to the local economy and demographic trends on a consistent basis since at least 1999:

List of comarcas

Alternative definitions

As the comarca boundaries are not defined in law, various other broadly similar combinations have been published depending on the date, range and purpose of the data collection. Examples include:
File:BIZKAIA.png|thumb|left|150px|Alternative arrangement in Biscay with 10 divisions, as defined by the Euskaltzaindia in 2016
Biscay province: the conurbations on either side of the Estuary of Bilbao within the Greater Bilbao comarca, known as the Left Bank and the Right Bank, are sometimes counted separately both from one another and from the city of Bilbao itself. Less commonly, the Getxo area on the Right Bank and the adjacent suburban Txorierri valley are grouped in a Uribe-Kosta district along with those in Mungialdea, while the Left Bank and the, the area's former mining zone, is merged into the mainly rural western Enkarterri comarca which previously governed the districts as a larger merindad, as was the case for the Right Bank in the Uribe merindad. The Hego Uribe area south of Bilbao tends to remain grouped with the city when other adjustments are made, or is linked with Arratia-Nervión if counted as an outlying zone.
Gipuzkoa province: the southern portion of the Urola Kosta comarca has been listed separately as . Similarly, the western part of Goierri has been recorded as the separate district. In the Donostialdea comarca, the eastern part centred on Errenteria and Pasaia has been referred to as Oarsoaldea, and in some cases this has been combined with neighbouring Bidasoaldea, with the Oarsoaldea name even being adopted by some for this larger area. Less commonly, the name has been used to refer collectively to the cluster of towns south of San Sebastián.
Álava province: the main deviation from the Eustat comarcas is in the representation of the capital Vitoria-Gasteiz, which alternatively has its own district comprising its urban municipality alone. In this alignment the western part of the rump Llanada Alavesa comarca is assigned to Gorbeialdea. The territory of Treviño is entirely surrounded by Álava, but is an exclave of the Province of Burgos and does not figure in the Basque considerations.

Population contrasts

As with the municipalities across Spain, the populations of each comarca vary widely; rural sectors of Álava cover only a few thousand residents each, while its capital Vitoria-Gasteiz is considered either to be in its own comarca or by far the most prominent component of the wider Llanada Alavesa, containing over 250,000 residents under either arrangement. In Gipuzkoa, the Donostialdea comarca includes not only the provincial capital San Sebastián but many of the smaller towns surrounding the city, leading to two further subdivisions being created in some contexts to represent these communities in a more balanced way. The most striking contrast is in Biscay, where the capital city Bilbao is just one part of the Greater Bilbao comarca which has 850,000 within its boundaries. Bilbao's eight city districts are comparable in population to four of the province's other more rural comarcas, despite in theory being two administrative levels below.