Asturias is the cider region par excellence in Spain. 80% of all cider in Spain is produced in Asturias. And so it has been since time immemorial, or at least since Indo-European people settled in this region. Historical evidence shows that during the Roman Invasion, cider was already produced in this region, whereas the earliest mention of cider production in other regions, like in the Basque Country, are of much later date - some thousand years later.
Other Spanish regions derived their knowledge about the art of making cider from Asturias. Even today Asturias is the absolute leader in Spain's cider production... and hey! those wooden barrels in which the Basques let their cider mature, happen to come from Nava in Asturias as well!
One more thing: Asturian Apple Cider is the only Spanish Apple Cider that has a Denominación de Origen.