4,000 total metres of climbing is on the agenda for the peloton in the 153 kilometre stage, with an undulating first half giving way to a monster pairing of climbs to put serious hurt on the legs.
The peloton shouldn't have too much trouble with the Category 3 Puerto del Castillo (6.8km at 4.5%) but it may give a breakaway the chance to extend their gap before the stage reaches the Category 1 Alto del Purche (9.1km at 7.6%).
Approaching after the riders have already gone 100 kilometres in the saddle, this climb should see the pressure begin to mount on the favourites, Jumbo-Visma may try early to pressure red jersey Remco Evenepoel (QuickStep AlphaVinyl) to sap his energy for the even harder finale.
The profile of Stage 15 of the 2022 Vuelta a Espana.
The first special category climb of this year's Vuelta, it was last used in the 2017 edition. Miguel Angel Lopez (Astana) took the win then, and will look to do the same when he returns tonight.
An out-and-out climbing specialist, Lopez finished second on yesterday's stage to Sierra de la Prevada and sits sixth overall with a 6 minute and 2 second deficit on the red jersey, so will be going full gas on slopes he knows all too well.
The main battle of the day will be between race leader Evenepoel and Primoz Roglic (Jumbo-Visma), the latter with a chance to further capitalise on his efforts in Stage 14 after he made up 52 seconds on the Belgian.
Second overall and still one minute and 49 seconds behind, Roglic has seemingly recovered from his poor start to the race, while Evenepoel could be going in the other direction after struggling to follow a strong move from Roglic in yesterday's finale.
"It's going to be a different finish tomorrow, we're going much higher," Evenepoel said after Stage 14.
"We'll see what it brings, I'm sure there's more benefit to sit in the wheel. I'll focus, keep my head and try to fight back."
Enric Mas (Movistar) is another who will be looking to attack as he sits third overall with a 2 minute and 43 second deficit to Evenepoel, and is sure to be familiar with the Sierra Nevada climbs as a native Spaniard.
This stage is sure to have fireworks and shape the rest of the race, so don't miss a minute as riders battle high altitude, steep slopes and soaring temperatures in an attempt to write their names into Vuelta history.
La Vuelta continues tonight with Stage 15, a massive 153 kilometre mountain with 4,000 metres of total climbing on the journey from Martos to the summit of Sierra Nevada. Watch the action from 9pm (AEST) on SBS On Demand before SBS coverage begins from 11:10pm (AEST).
