On the day after a Primož Roglic put on a show on the fantastic Lagos de Covadonga climb, the Vuelta a España peloton will, somehow, be tested even further.

With the most challenging profile of any stage in the race, Thursday’s stage 18 will be the best remaining opportunity for the overall hopefuls to challenge the defending champion at this Vuelta.

“Tomorrow is a crazy hard day,” Sepp Kuss said after finishing stage 17.

That’s a pretty fair description for the stage 18 profile. The race will will cover two Cat 1s and a Cat 2 before what promises to be an intense finale as the Spanish Grand Tour makes its first ever visit to the Altu d’El Gamoniteiru.

The highest paved road in the Asturias region, the Altu d’El Gamoniteiru (that’s its name in Asturian; it’s the Alto del Gamoniteiro in Castilian Spanish) is situated south of Oviedo, right next to the famed Alto de l’Angliru. The latter ascent is ever-so-slightly steeper, but the Altu d’El Gamoniteiru is longer. All told, the Altu d’El Gamoniteiru is 14.6 km in length at a whopping 9.8% average gradient, ascending up to 1,776 meters.

The climb starts out quite hard, eases off for just a moment near the midway point, and then surges steeply upward again. A section at 17% awaits in the final kilometer for good measure. As Asturian pro Dani Navarro (Burgos-BH) told AS earlier this year, “That last kilometer and a half is very demanding. It seems like it never ends! It becomes interminable.”

With such a grueling finale to a stage that will have already taken riders over three tough categorized climbs before they arrive, it will be a huge test for the climbers – but also a huge opportunity, the best one left in a race nearing its conclusion. After an intermediate day on stage 19, there are some tough Cat 2 climbs on stage 20, but nothing that will come close to the brutal finish on Thursday’s stage. And with an individual time trial to close out the race on stage 21, where Olympic time trial champion Roglič will likely gain more ground on his rivals, there will be no better time for the likes of Movistar’s Enric Mas and Miguel Ángel López and the rest of those in the GC picture to try their luck. Plus, further down the GC standings, others will be eyeing the two podium spots that Mas and López are currently in pole position to take.

For his part, Roglič echoed his Jumbo-Visma teammate Kuss in calling the final climb that awaits “crazy hard,” and saying that “still anything can happen” after stage 17, but he does expect that “everyone will be tired” following the trip to Lagos de Covadonga. Movistar’s Miguel Ángel López, meanwhile, wasn’t sure what to expect for himself or his teammate on the coming stage.

“I don’t know how Enric’s legs and mine will do tomorrow, but I think we did well today, keeping the front and together,” he said after Roglič’s triumph on Wednesday. “Roglič completed a stunning performance, then it’s pretty much even between the rest. We’ll see tomorrow.”

Roglič’s hefty GC advantage – he has 2:22 on second-placed Mas, and way more to the rest of the field – won’t be easy to overcome, of course, and it would undoubtedly be a huge surprise for anyone to overhaul him at this point.

That said, if there was ever a climb to crack the red jersey on, it would look like the one that awaits on Thursday.