Madrid - Britain's Chris Froome headlines a star-studded field, looking to become the first man to win the Tour de France and Vuelta a Espana in the same year since 1978, when the third Grand Tour of the season gets underway on Saturday.
Froome is aiming to match Frenchman Bernard Hinault's feat in winning back-to-back Grand Tours in France and Spain 38 years ago.
However, the presence of three-time winner Alberto Contador and Movistar duo Nairo Quintana and Alejandro Valverde promises to push Froome to the limit across three weeks and 21 stages in Spain, if he is to add to an already successful season.
Froome was imperious in claiming his third Tour title in Paris last month but, despite multiple attempts, the Vuelta with its gruelling climbs in searing heat has so far eluded Froome and Team Sky.
The Kenyan-born rider finished second in his breakout Grand Tour in 2011 and in 2014, but was forced to pull out of last year's edition after just 11 stages due to a broken bone in his foot.
Froome arrives back in Europe having missed out on his quest for double gold at the Olympics, claiming just a bronze in the time trial, and finishing down in 12th in the road race.
"It's already been a great summer for both myself and the team, but the Vuelta is another big challenge for us," said Froome.
"It's a race I really enjoy and where I guess you could say I have unfinished business, so I'm looking forward to getting started."
However, despite Sky boasting another strong team around Froome, including 2014 world champion Michal Kwiatkowski of Poland in his first Grand Tour appearance for the British outfit, Froome will be without a host of team-mates key to his Tour de France triumphs.
Geraint Thomas and Wout Poels have not been selected, whilst Mikel Landa and Nicholas Roche miss out through injury and illness respectively.
History also beckons for Contador if he can land a fourth win on home soil in just his fourth appearance in the race to match Roberto Heras's record of four wins in the race.
Contador endured a nightmare Tour last month as he crashed on the opening two stages before admitting defeat and pulling out on stage nine.
However, having also missed the Olympics due to his injuries, he returned to win the Tour of Burgos in his homeland earlier this month.
"Certainly, my goal at the Vuelta is to fight for victory," said Contador, who will lead the Tinkoff-Saxo team for a final time before joining US team Trek Segafredo next season.
"This will be my last Grand Tour with Tinkoff and I would like to finish it in the best way."
The final Grand Tour of the year also offers the chance for Colombian Quintana to make amends for his disappointing Tour display, despite climbing into third place in the final week.
Quintana never threatened Froome as expected, but the hilly terrain in Spain with 10 summit finishes and just one individual time trial should suit him better.
Meanwhile, 36-year-old Valverde is aiming to become the first man to register top 10 finishes in all three Grand Tours in one season, after finishing third at the Giro d'Italia and sixth at the Tour de France.
The race starts with a 29.4km team time trial in the Galician city of Ourense, with most of the mountain finishes coming in the second week as the riders trek across Spain's northern coast.
The third week is spent largely in the Valencia region with the 39km individual time trial on stage 19 likely to be crucial before a parade around Madrid on September 11.