What is Alto de l'Angliru? Asturias climb is an awe-inspiring and alarmingly difficult feature in the Vuelta a España

The Alto de l'Angliru, known mostly as 'the Angliru', conjures both fear and defiance for cyclists. A legendary mountain pass in Spain's Asturias region, it is generally accepted to be the most difficult climb in Spain.

The full length from bottom to top is 12.4km with an average gradient of 9.7%. It's the second half of the narrow, twisting road that gives the climb notoriety as it winds beside steep walls with rocky outcroppings and provides sweeping views of the Asturias region of northern Spain without obstructions of trees. Signs on the road also alert casual riders to how steep each section is.

On a section 3km from the summit the gradients push up to 20%, with one section reaching as high as 23%. That is why that part of the mountain is called Cueña les Cabres, pass of the goats, as only farm animals were common on the original gravel path.

The tourism website for Asturias goes as far as to call this stinging segment "a section that goes against all logic". I suppose that makes it truly worthy of an hors categorie designation.

Tourism officials also explain how the mountain got its name, as farmers used the Latin word 'angulum' for the base of the name to describe an angled or out-of-the-way place.

History at La Vuelta

It wasn't until 1997 that the full length of the Angliru road was paved for vehicles to pass, with Cueña les Cabres covered by tarmac two years later just for the Vuelta a España. Since the Angliru's introduction in 1999 the climb has been used in the race nine times, with 2025 marking the 10th occasion.

Spaniard José María Jiménez (Banesto) etched his name in the record books as the first conqueror of the climb, which featured on stage 8 of the 1999 Vuelta. He would win the mountains classification that year for a third time. Italian Gilberto Simoni (Lampre-Daikin) won the mountain stage the next year. After a one-year hiatus, l'Angliru returned on stage 15 in 2002 won by Spaniard Roberto Heras (US Postal Service).

The only rider to have conquered l'Angliru twice at the Vuelta was Alberto Contador, with the Spanish climber winning in 2008 for Astana and 2017 for Trek-Segafredo.

Other riders to dominate the climb in the other four appearances were Dutch rider Wout Poels (Bahrain Victorious) in 2011, Frenchman Kenny Elissonde (FDJ) in 2013, Hugh Carthy (EF Pro) of Great Britain in 2020 and most recently in 2023 by Primož Rogič (Jumbo-Visma).

The ascent

The first six kilometers are relatively consistent with gradients of 5%-7%, and brings riders to a one-kilometre reprieve of an almost flat section that leads to a recreation area of Viapará.

The second half of the climb has no other access roads, so it is the only path to the summit. It also marks the end of the 'easy' part of the climb, and the pitch of the road becomes perceptibly steeper, rising to 13% and 15% on the next kilometre.

Several sections have been named - Llagos (14.5%), Les Picones (20%), Cobayos (21.5%) and the mind boggling Cueña les Cabres (23.5%), with signs along the way to announce the gradients, for those who want to know.

Between kilometres 7 and 9.5, the pitch remains a consistent 11-12%, with a sharp right-hand bend at kilometre 8.3. The gradient kicks up to 15-17% as Cueña les Cabres hits at kilometre 10.5, where the gradient tops out at 23.5% for about 500 metres.

The decrease to 12% gradient at kilometre 11 seems allows a rider to catch their breath, but then a small bump at 20% hits several hundred metres beyond. When the gradient drops to 6%, the top of the climb is only 500 metres later.

2025 Vuelta

At the 2025 Vuelta, half of the 21 stages are uphill finishes, with the Angliru the headliner on Friday, September 5 for stage 13. Among the 10 appearances of the summit finish at the Grand Tour, it has most commonly been slotted in the second week, and has only been the culminating climb of the race on stage 20 twice, 2013 and 2020.

This year the climb punctuates the 202km journey from Cabezón de la Sal and riders will accumulate 3,964 metres of elevation gain. It's the longest stage of the three-week race.

Two-time Vuelta runner-up Fernando Escartín referred to l'Angliru as 'feared' and had this to say about the climb after the route announcement for this year: "Facing La Cueña les Cabres with almost 200km behind them will be a crucial test for the favourite riders who, should they have a bad day, can kiss La Vuelta goodbye".

The hors categorie climb may not reach the highest point of the Vuelta (that is reserved for stage 20 at Bola del Mudo at 2,251 metres above sea level), but it guarantees high-ranking heroics for riders in search of a career achievement and towering tactics for teams positioning their GC leaders.