Briton Chris Froome's bid for a fifth Tour de France title will come on the shortest route of the 21st century and see a return to Alpe-d'Huez.
A hilly time-trial in the Basque Country could be decisive on the penultimate day of the race, which begins on July 7 and concludes in Paris on July 29.
Organisers unveiled the route in Paris on Tuesday. Alpe-d'Huez is not likely to be as decisive as it was in 2015 when Froome won overall by one minute 21 seconds.
Froome (Team Sky) clung on to claim a second Tour victory, after his 2013 triumph and crashing out of the 2014 edition, when struggling with a chest infection on Alpe-d'Huez, where Colombia's Nairo Quintana's attack up the 21-hairpins almost brought him victory.
The 105th edition of the Tour will see a reduced peloton, with each team reduced by one rider from nine to eight in Grand Tours in a bid to make the racing less controllable. Some suggested it was specifically targeted at Froome's dominant Team Sky squad.
Froome has won four of the last five editions of the Tour, while Sir Bradley Wiggins won the yellow jersey in the 99th edition of the race in 2012 to give Team Sky five victories in six years.
It was already known the race will begin on Noirmoutier-en-l'Ile and the peloton will cross the Passage du Gois causeway. The 2011 race had the same start in the Vendee region of western France.
The 3,329-kilometres route features a very short 65km mountain stage in the Pyrenees which is the shortest road stage since the elimination of half-stages.
Just 15km of the race takes place outside of France, in Spain on stage 16, while a team time-trial on stage three could play to the strengths of Froome's Team Sky squad.
Tour director Christian Prudhomme said: "We especially wanted to emphasise stage variety and the routes that may prove decisive, whilst combining legendary climbs with brand new ascensions or ultra-dynamic formats, to provide a vision of modern and inspired cycling."
Froome in 2017 won both the Tour and then La Vuelta to show his status as the pre-eminent rider of his generation.
There will be a reminder of his one Tour failure in recent years in 2018, too, as the race returns to the cobbles of northern France used in the Paris-Roubaix one-day race.
Three crashes in two days, resulting in a fractured hand and a fractured wrist, saw Froome abandon the 2014 Tour which had begun in Yorkshire. But he returned to the same terrain a year later to silence any doubters and went on to win the race.
Froome received the prestigious Velo d'Or award - the Velo magazine rider of the year prize - for the third time, following wins in 2013 and 2015.
Tour organisers Amaury Sports Organisation (ASO) also announced that the fifth edition of La Course by Le Tour, the women's race, will take place on stage 10, prior to the men's passage along the same route.