From Gérgal to the Calar Alto observatory it is 14 miles (22.5 km) at an average of 6.4%: 4,708 ft (1,435 m) of climbing to about 7,087 ft (2,160 m). The three databases we checked agree very closely (22.4-22.6 km and 1,429-1,441 m); the summit elevation varies between 2,146 and 2,162 m (7,041 and 7,093 ft) depending on where it is measured.
What the climb is like
- Gérgal to Venta Luisa (about 12 miles / 19.3 km). From exit 362 on the A-92 you climb the road toward Serón. It is a long, steady climb with no shade except for some pine forest near the top. The hardest part is the nine hairpins before the Venta Luisa junction, at 6,463 ft (1,970 m).
- Venta Luisa to the observatory (about 2.1 miles / 3.3 km). Turn left onto the paved observatory road; about 623 ft (190 m) of climbing remain. The track to the right heads toward the Las Hoyas hut and Velefique.
The maximum grade is around 11-11.6%. The surface is in perfect condition and hardly any cars come by. We do not publish a segment profile.
Its history
At the top is the Calar Alto Astronomical Observatory, close to the highest peak in the Filabres (7,113 ft / 2,168 m). The Vuelta a España has finished here in 2017, won by Miguel Ángel López on the Lorca-Calar Alto stage, and in 2026, when Jakob Omrzel won the Vera-Calar Alto stage. CyclingCols also records Vuelta crossings in 2004, 2006 and 2009.
When to go, water and traffic
In summer, this shadeless climb is brutal at midday. The best seasons are spring and fall; in winter it can snow at the top. There is only one fountain, around km 18 (mile 11), before Venta Luisa. Traffic is almost nonexistent. Nearby is the Alto de Velefique, another of the big Filabres climbs, plus other sides from Tíjola (19.8 miles / 31.8 km), Serón and Bacares.
What gearing to use
A 34x28 or 34x30 is enough for most riders. At 3 W/kg (watts per kilogram of body weight) and 159 lb (72 kg), you ride about 6.8 mph (11 km/h) on 8% and 5.6 mph (9 km/h) on 10%; on a 34x30 that is 77 and 63 rpm. It is more than an hour and a half of climbing for a recreational rider, so go lower rather than higher. Run the numbers in the gear calculator.
Tips
- Leave Gérgal with two full bottles: there is no water until km 18.
- In summer, start at dawn.
- Bring a warm layer: it is about 18 °F (10 °C) colder at the top than in the valley.
Frequently asked questions
How long does it take to climb Calar Alto from Gérgal?
A 159 lb (72 kg) rider on a 21 lb (9.5 kg) bike takes about 1 hr 42 min at 3 W/kg (216 W), 2 hr 01 min at 2.5 W/kg and 1 hr 19 min at 4 W/kg. Work out your own time with your weight and power in the calculator on this page.
Who has won on Calar Alto in the Vuelta a España?
Miguel Ángel López in 2017 and Jakob Omrzel in 2026.
Where is there water on the way up Calar Alto?
There is a fountain around km 18 (mile 11), just before the Venta Luisa junction. Before that, nothing: leave Gérgal with full bottles.