Alto de l'Angliru (alternative name: La Gamonal) is a steep mountain road in Asturias, near La Vega-Riosa, in northern Spain. It is one of the most demanding climbs in professional road bicycle racing and is often used in the Vuelta a España stage race.
The organizers of the Vuelta a España wanted a mountain to rival the Alpe d'Huez and Mont Ventoux in the Tour de France and the Mortirolo Pass in the Giro d'Italia, which would go on in 2003 to add one of the world's most demanding climbs, the Zoncolan, in an attempt to compete with the new Spanish climb. The Angliru was first included in 1999, on stage eight from León. José Maria Jiménez won after catching Pavel Tonkov a kilometer from the finish. He dedicated the win to Marco Pantani, disqualified from that year's Giro d'Italia, saying: "I dedicate it to Pantani by everything that he has suffered in this time".
The top of the climb is 1,573 metres (5,161 ft) above sea level. The height difference is 1,266 m (4,154 ft). The climb is 12.5 kilometres (7.8 mi) long, an average of 10.13%. It is near 24% at its steepest. The first 5 km (3.1 mi) are an average of 7.6%— stiff but not over-demanding for world-class cyclists. The sixth kilometre lessens to 2.1% and has a short descent. The last half of the climb is more severe. From six kilometres to the summit, it averages 13.1%. The steepest part, the Cueña les Cabres at 23.6%, is 3 km (1.9 mi) from the summit. There are two later ramps at 18% to 21% (sources vary).
During stage 15 in 2002, riders climbed the Angliru in rain. Team cars stalled on the steepest part, some unable to restart because their tires slipped on messages painted by fans. Riders were caught behind them and others had to ride with flat tires because mechanics could not reach them. David Millar crashed three times and protested by handing in his race number a metre from the line. The judges ruled he had not finished the stage and he left the race. He regretted his temper - he had been ninth - and apologised to his team.