The Alto de L'Angrilu.
A name that sends a chill down the spine of even the leanest and meanest of mountain goats. This climb has catapulted riders into the annals of history for both the good and the bad.
At 12.5km long, the average percentage of 10.1% is almost deceptive with the steepest parts of the climb coming after half way. The Angrilu continuously touches 20% throughout the final six kilometres, maxing out at 23.5%. These brutal gradients will see the peloton climb 1,241m from the base of its climb to its eventual summit.
The unsettling nature of the ever changing gradient means that riders cannot find a rhythm whilst climbing, making the whole experience uncomfortable and unpredictable.
The Angliru cruelly rounds off a tough final 50 kilometres on Stage 20, with two category 1 climbs acting as hors d'oeuvres to the headlining act.
Following suit with Stage 15, Stage 20 from Corvera to the Angliru is only 119.2km long. With a lack of kilometres on the stage when compared to the amount of vertical gain, this day will see riders either climbing or descending almost all day.
This is bound to lead to aggressive and fast racing from the flag drop.
Falling on the penultimate day of the race - with the final stage being a processional stage into Madrid - this final playground could be the deciding factor in who takes the overall title.
This would not be the first time that the Angliru had decided the winner of the Vuelta a Espana. British fans will remember the disappointment the climb brought in 2011.
Sitting comfortably in the lead, Sir Bradley Wiggins saw his dreams of Vuelta glory shattered on the ascent of the Angliru. Throwing caution to the wind, Spaniard Juan Jose Cobo went on the attack, distancing Wiggins and trusty domestique Chris Froome, riding into red.
The time that Cobo banked on the Angliru was enough to see him through to Madrid, causing one of the biggest Grand Tour surprises in recent history.
Being the very last test of the peloton, it would be of no surprise if the general classification experiences a dramatic reshuffle so late in the race.
With this Stage coming so deep in the race, it is hard to predict who will be gunning for glory and be looking to utilise the climb to their own advantage. However, if all the expected protagonists are still present this late into the Vuelta, there are a few riders that we can expect to ride well.
Having experienced the climb in 2011, Chris Froome will know what to expect and he certainly has the team to help him. Currently on Team Sky's long list sits Wout Poels and Kenny Ellisonde. Ellisonde was the victor on the Angliru the last time the Vuelta visited the climb and Poels has placed well on the climb in the past.
The style of the climb, with its varying gradients, does not exactly suit Froome, who prefers a steadier gradient. Yet, Froome is know to thrive off of the difficult, and smelling blood, could use this monstrous climb to stamp his authority as the best climber in the world.
With the constant pitches of 20%, another rider who may prosper on this climb is Esteban Chaves (Orica-Scott). The talented Columbian has proven his worth on the steep stuff and could certainly use the Angliru to his advantage.
Weighing just 55kg, he should be able to deal with the steepness of the climb well, and with victory at the 2016 Tour of Lombardy, Chaves has previous of delivering powerful efforts.
Injury and personal loss has meant that Chaves has been less prevalent this season, but with previous success at the Vuelta, the 27-year old could be a contender for overall victory come Stage 20.
The irregularity of the climb would lend itself to an irregular climb. After two stages of the Tour de France claiming he does not use power to determine when to attack, the Angliru could suit Warren Barguil.
Barguil's climbing form was clearly apparent at the Tour, taking the polka dot climbing jersey and the summit finish on the Col d'Izoard. With the Tour in his legs, Barguil may be too tired, but if he is in good condition, do not be surprised if Barguil launches an audacious attack on the slopes of this final mountain.
The Angliru could be the deciding factor of this entire race. Propping up such a short stage, it is most likely going to produce some very exciting racing. With live coverage of this stage starting at 1pm on Eurosport, we recommend this as one of the stages that get your full attention.