The penultimate stage of this year’s race could prove vital in deciding the final destination of the red jersey, as it concludes with the second ESP-rated climb of the race.

Battling brutal slopes on the 12.7km ascent, the ascent to Puerto de Ancares offers an opportunity to make big gains overall.

An average gradient of 8.7 per cent, with some sections nearer to 20 per cent, means the stage will conclude with an epic battle on the mountain before the following day’s time trial.

Fancy tackling it yourself? The HC-rated Strava climb in Galicia peaks at 1,639 metres and has been tackled by just 38 Strava users to date.

First among them is the only man to have gone under an hour on the climb – setting an average speed of 12.2km/h, with an estimated power output of 303 watts.