Aller

Aller is a municipality in the Autonomous Community of the Principality of Asturias, Spain. It is bordered on the north by Mieres, on the south by the province of León, on the east by Laviana, Caso, and Sobrescobio, and on the west by Lena.
The municipality is crossed by the Aller River, which flows into the Caudal. Near the confluence, the Aller forms a deep valley between steep hillsides covered with forest. The municipality, along with those of Lena and Mieres, forms the coal-rich basin of the Caudal. The principal economic activity has been coal mining, especially in the lower part of the valley, while agriculture and ranching are also important. The towers of coal mines and the buildings of the mining communities dominate the landscape.

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