The popular 10km trail to reach the base of Naranjo de Bulnes begins at the mouth of the Garganta del Cares in the village of Poncebos, 6km from the popular tourist town of Arenas de Cabrales.
But if it was meant as a simile, it could also be taken literally -- because in a number of these caves, the local speciality, Cabrales cheese (a blue cheese similar to Roquefort) is quietly ageing in the gloom.