PARIS -- Like a giant roller-coaster from start to finish over five mountain ranges, next year's Tour de France will feature new summits and only a few time-trial kilometres.

That should delight pure climbers like defending champion Egan Bernal.

"With just one time trial, and moreover one with a very steep finish, I really like it," said Bernal, who at 22 became the youngest Tour winner since World War II in July. "I'm a climber so I prefer to have this kind of stages. It will be a different Tour. Really, really, hard, with a lot of steep climbs."

Beginning in the Riviera city of Nice, the 3,470-kilometre three-week race will send the pack of contenders over two big climbs culminating above 1,500 metres as soon as Stage 2, and riders will have to cope with a summit finish in the Alps only four days into the race.

"Starting from the south of France gives us plenty of possibility," race director Christian Prudhommne said ahead of Tuesday's race presentation in Paris. "We will be in the foothills of the mountains. Two mountain passes over 1,500 metres as soon as the second day, it's something never seen before in Tour history. And two days later there is a mountain top finish at Orcieres-Merlette. The mountains will be the central theme."

While organizers peppered a total of 29 climbs over the Alps, the Pyrenees, the Massif Central, the Jura and the Vosges, there will be only one time-trial, taking place on the penultimate 36-kilometre stage to the ski resort of La Planche des Belles Filles -- a brutal and tortuous slope that has become a Tour classic in recent years. That is where the final battle between Bernal and his challengers should take place before the race's traditional finale on the Champs Elysees on July 19.

"That course for next year is brutal," said four-time Tour de France champion Chris Froome, who missed the race this year because of an injury and mastered the Planche in 2012. "It's probably the hardest Tour route I've seen in the last five-six years."

Tailor-made for the likes of Bernal and French climber Thibaut Pinot, the 2020 Tour will start a week earlier than usual because of the Tokyo Olympics.

"Some riders will leave right after the final stage for Japan," Prudhomme said.

Because of the strong focus on the mountains, the race route is ignoring the northern half of France. After a first incursion into the Alps, the peloton will head southwest toward the Pyrenees via the Massif Central, where it will tackle another mountain top finish at the Mont Aigoual during Stage 6.

Two big stages are then scheduled in the Pyrenees before a maritime interlude on the Atlantic Coast linking the island of Oleron to the Ile de Re. As often when competitors ride by the sea, strong winds could play havoc with the peloton if the gusts pick up.

The race will then head back into the heart of France and stop in the town of Sarran, the political fiefdom of late French president Jacques Chirac, who died last month.

"Sarran was obviously on the program before Jacques Chirac's death," Prudhomme said. "The finish will be staged in front of the Chirac museum."

Following a pair of new summit finishes at Puy Mary in the Massif Central and the Grand Colombier in the Vosges, a mouthwatering trilogy of Alpine stages will then help decide the outcome of the race. Stage 17, arguably the toughest, features the Col de La Madeleine and another novelty, the Col de La Loze, the Tour's highest point this year at 2,304 metres. The traffic-free pass between the ski resorts of Meribel and Courchevel was opened to cyclists this year after a forest track was paved by local authorities.

The last six kilometres of the climb are particularly difficult, with very steep sections and sharp turns.

"This is crazy, something that does not exist elsewhere. It's like the Huy Wall, but at 2,000 metres above the sea," Prudhomme said, referring to the short and tough climb highlighting the Fleche Wallonne classic race.

"We looked for difficulties everywhere," Prudhomme said. "I believe this route respects the Tour history, with tough, emblematic slopes, and an extraordinary landscape."