Arenas de Cabrales is the capital, if that is the word, of one of Europe's most pungent cheeses. Cabrales is a blue made from cow's milk, sometimes blended with sheep and goat, and it matures in natural limestone caves in the hills above the village where cool, damp air does the work that a refrigerator would elsewhere. It looks like something that has been left in a cellar, and it tastes like a punch to the tongue followed by a hug. Locals eat it with cider, or spread on bread, or melt it over beef. A late-summer cheese fair in the village celebrates it. You can buy a wedge here to take home, though think about where it will ride.
The village sits low on the river Cares, tucked where the valley starts to funnel toward Poncebos, the trailhead for the famous Cares Gorge path. The AS-114 follows the water through limestone country, and the riding is the point. Corners come in tight, readable sequences, the road narrows through gorge sections, and every few kilometres the rock walls open to show a sheep meadow and a stone barn. Traffic is thin outside August, and the surface is mostly good, though patches of gravel and damp shade are worth respecting. Heading east and then north, you drop toward the coast and Llanes, with the sea suddenly bright at the end of the valley.
Beyond the village the high ground is serious: the Naranjo de Bulnes, also called Picu Urriellu, a limestone tower of about two and a half thousand metres, is the great climbers' prize of the central massif, though you need to walk to see it up close. From the road you mostly get its neighbours, pale and jagged against the sky. Brown bears and wolves live in the Cantabrian mountains, though you will not see one from a bike.
For practicalities, Arenas has small shops, cafés and a couple of places selling cheese. Fuel is better planned in Llanes, about fourteen kilometres away, or in Cangas de Onís to the west, and since mountain hairpins burn through a tank faster than you think, top up before you commit. A plate of local cheese and a glass of cider is a better lunch than it sounds.