San Martín del Rey Aurelio

The castillette at Pozo Entrego rises like a rust-coloured cathedral against the green valley walls, its steel headframe still lowering miners' cages even though the last shift ended decades ago. This is San Martín del Rey Aurelio's most honest monument—not pretty, not polished, but utterly compelling. The 16,000-person municipality spreads along the Nalón valley floor at 200 metres above sea level, yet the surrounding limestone walls climb to 1,000 metres within a 30-minute walk from any high street. That vertical drama shapes everything here: the weather, the walking, the very reason this place existed at all.

The Valley That Coal Built

Drive the AS-117 from Oviedo and the transition happens fast. First the apple orchards, then suddenly you're threading between company housing blocks painted ochre and pistachio, built flush against the road because space was precious and coal wagons needed every inch of valley floor. Sotrondio, El Entrego, Blimea—these aren't separate villages so much as one 8-kilometre chain of mining neighbourhoods, each with its own bakery, football pitch and social club still marked "Sociedad de Socorros Mutuos."

The Pozo Entrego complex (free, always open) rewards ten minutes of looking properly. The 1923 headframe stands 45 metres high; stand beneath it and you feel the valley's narrowness—the thing was built tall because it had to be, not for grandeur. The adjacent washery building, all riveted girders and conveyor mouths, now hosts occasional art shows but mostly just exists, which feels right. No gift shop, no audio guide, simply the smell of machine oil that never quite leaves.

Walk five minutes uphill from El Entrego's main road and the terraces change. Suddenly it's two-up-two-down miners' cottages with 1950s bathrooms tacked on, then inter-war semi-detached houses boasting tiny front gardens where leeks grow where roses might be expected. The architectural timeline runs backwards as you climb—each generation building slightly higher, slightly better, away from the river's damp breath but still within walking distance of the pit gates.

Walking the Miners' Skyline

San Martín rewards those who abandon the car. From Sotrondio's top road a signed footpath (yellow-white stripes) climbs 250 metres in 45 minutes to the Mirador de la Peñona. The track follows the old aerial ropeway that once carried coal buckets; concrete pylons every hundred metres make navigation idiot-proof even when cloud rolls in. At the top the valley floor spreads like a map—red-tiled roofs in neat rows, the Nalón river glinting, and beyond it the opposite wall where buzzards wheel at eye level.

The full circular route takes three hours and drops down to Blimea through hawthorn lanes where wild asparagus grows in April. Stout shoes suffice; after rain the clay sections become properly slippery so carry a walking pole or improvise with a fallen eucalyptus branch. In winter these paths can ice over—locals fit chains to their boots and still stride past while visitors slide ignominiously on their backsides.

Lower-level options exist. A 4-km there-and-back follows the Nalón's east bank from El Entrego to La Peña, mostly flat on a former railway bed. Kingfishers flash turquoise between the alder roots; information boards explain how miners released cage-washing water here, turning the river black for decades. Today the water runs clear enough to spot trout, though eating them isn't recommended—old mercury residues linger in the sediment.

When the Pubs Close at Nine

Evening entertainment requires adjustment. Apart from summer fiestas, nightlife means choosing between four bars in El Entrego or three in Sotrondio, most shuttered by 22:30. Bring a pack of cards, download a podcast, embrace the Spanish sobremesa—that chatty hour after dinner when no one rushes to leave the table. Locals treat cider pouring as performance art: a 200-millilitre splash from shoulder height, drunk immediately while the bubbles still fizz. Try it once and wear dark clothes; the floor gets sticky for a reason.

Food is sturdy rather than delicate. Estofado de nabos—pork belly and turnip stew—appears on Thursday lunch menus for €9 including bread and a bottle of gaseosa. Stuffed onions (cebolles rellenes) taste like Spanish bubble-and-squeak, all sweet vegetable and béchamel comfort. Vegetarians survive on tortilla and cheese from La Peral dairy, sold at the Saturday morning market in El Entrego's municipal car park. If you need oat milk or kale, bring it with you—this is not that Spain.

Rain, Roads and Realistic Expectations

August brings the Cebolles Rellenes fiesta and the place jumps—brass bands at midnight, queues for cider stretching round the block, apartments booked a year ahead by returning Asturian families. Spring and autumn offer milder weather and empty streets; April showers can last all morning, then give way to 18 °C sunshine by lunch. Winter sees the valley floor fog-bound while the hilltops bask in bright sun—a temperature inversion that feels magical until you realise the same fog trapped coal smoke for a century.

Getting here without a car means riding the Feve narrow-gauge railway from Oviedo—two trains an hour, 50 minutes, €4.35. The line hugs the river, passing through tunnels where phone signal dies, emerging to views of allotments planted with kale and kiwi fruit. Last buses back from Oviedo leave at 21:05; miss one and a taxi costs €40, more than many guesthouse rooms. Hire cars should be booked in Oviedo or at the airport—local firms in El Entrego offer basic Fiats but close Saturday afternoons without fail.

San Martín del Rey Aurelio doesn't seduce; it simply is. Come for the mining heritage, stay for the valley walks, leave understanding why half of northern Spain once depended on this ravine of coal and steel. Pack waterproofs, patience and an open mind. The castillette will still be there, waiting to remind you that some places earn their beauty the hard way.