Cycling's Vuelta a España embarks Friday with defending champion Primoz Roglic chasing an unprecedented fourth straight victory over a mountainous 3,280km route that begins, however, on the flatlands of the Netherlands.

After the Giro d'Italia started in Budapest and the Tour de France in Copenhagen, both to rousing support from roadside fans, the final grand tour of the season begins its 21-day odyssey with a 23km team time-trial around Utrecht.

It is home terrain for Slovenian Roglic's Jumbo team. They are Dutch-based and include three Dutch riders in Sam Oomen, Robert Gesink and Mike Teunissen.

"We have a nice and balanced team at the start that can optimally support Primoz in all areas," Jumbo director Merijn Zeeman said.

The flat Dutch terrain means stages two and three are likely to culminate in mass sprints, so Jumbo's best chance on home soil is the opening day team race.

The 23 teams, which start with 184 riders, transfer to Spain on Monday, and start climbing at once with all six stages before the next rest day in medium or high mountains.

The race winds through the rugged terrain of the Basque Country and Asturias, where plenty of travelling Dutch fan are expected.

Stage five ends in Bilbao, near Frank Gehry's landmark Guggenheim museum, which is celebrating its 25th anniversary.

Stage eight and nine in Asturias offer climbers the chance to gain serious time.

After a second rest day, the race swoops south where the kind of sizzling temperatures that effected the Tour de France could play a roll.

An individual time-trial on stage 10 should provide a minor shake up while the cliff-perched city of Ronda hosts the start of stage 13.

A mountaintop finish, more than 2,500m high in the Andalusian Sierra Nevada may provide some drama on stage 15.

The race might only be settled on stage 20 with a series of climbs designed to produce a final showdown on the road towards Madrid.

Open field

Quick Step starlet Remco Evenepoel targets his first Grand Tour at 22 and was the bookies tip for triumph before Roglic was declared fit on Monday.

The rigours of a 21-day Tour will test Evenepoel, who has won several shorter tours, but he will be chaperoned by the world champion Julian Alaphilippe, as co-leader.

"He doesn't start as a favourite, and we will just take it day by day," said Quick Step sports director Klaas Lodewyck.

"It's a whole new adventure for him," Lodewyck said of the rider with 11 wins this season, including a resounding triumph at Liege-Bastogne-Liege.

Former Giro champion Richard Carapaz leads a youthful Ineos line up and, after a narrow miss at the Giro in May, the reigning Olympic champion cannot be ignored.

Ineos director Rod Ellingworth expects "an exciting edition of the Vuelta" with some "outstanding racing".

Powerful roller Dylan van Baarle and the climbers Pavel Sivakov and Tao Geoghegan Hart provide ample back up in an otherwise youthful Ineos line up.

Giro champion Australia's Jai Hindley and British climber Simon Yates both appear to have the credentials to target at least a podium shot.

But several of cycling's hottest riders are missing with Egan Bernal, Jonas Vingegaard and Tadej Pogacar all sitting out this Vuelta.