Alto de l’Angliru is the Ultimate Cycling Ascent in Asturias

# Alto de l'Angliru

Alto de l'Angliru sits at a brutal 1,558m (5,111ft) above sea level in Asturias, northern Spain, and it's honestly one of the most punishing climbs you can attempt on a bike.

Starting from the paved RI-5 Road north of Porció, this 8.5km (5.28 miles) stretch to the summit (also called Gramonal) is fully paved but absolutely relentless. What began as an old cattle track has become a dream—or nightmare, depending on your perspective—for cyclists worldwide. The road is refreshingly quiet during weekdays, though you'll encounter more company on weekends.

Here's where things get serious: the gradient hits a jaw-dropping 23.5% at its steepest points, with an average of 10.68% and a total elevation gain of 908 meters. There's virtually no mercy here—just when you think you've found your rhythm, there's another brutal ramp waiting. Even that brief downhill stretch a few kilometers in gets swallowed up by the punishing 21% section that follows, so don't count on catching your breath.

This climb has earned its reputation in professional cycling since its first appearance in the Vuelta in 1999. It's genuinely in the same conversation as Alpe d'Huez and Zoncolan, and some pros have actually refused to tackle it. The undulating nature means it's a relentless series of gut-punching climbs rather than one steady grind.

Located within Las Ubiñas-La Mesa Natural Park, expect frequent fog and rain even in summer—conditions can be particularly treacherous. Winter often renders the road completely impassable due to heavy snow, so timing your attempt carefully is essential.