The 5 most important climbs of the 2025 Giro d'Italia

The 2025 Giro d'Italia has been revealed and features a route with plenty tricky stages, including all kinds of mountain stages. We take a look at what are perhaps the five most important climbs in the whole route and why, including some mythical Alpine passes.

This will be a route with two individual time-trials, two hilly stages in Albania to start off the race but one which will have high mountains only from the 15th stage onwards. It will be key for the riders to save their best legs for the final week of the race, as that's where the overall classification is likely to be decided.

The climb to Tagliacozzo is by far the hardest in the race and nowhere near the most important. But this ascent, which ends the seventh stage in the race, will be a key moment in the race as it's the first summit finish and is hard enough to create differences. On it's slopes we will have a better idea of the form of the main GC contenders and what they can seriously aim for in this race.

A stage in the Appeninnes which features climbing from start to finish, it will then culminate in the 12-kilometer ascent that averages 5.5%. The final 2.4 kilometers however average 10% and this will be terrain to create serious differences. If the riders do not come to this climb with their best form they risk losing important time and go into the gravel stage or potentially the second half of the race already on the back foot.

For what it's worth, the Giro organizers implemented the same formula as in 2023. Following the final rest day, riders take on a brutal day in the mountains with several difficult ascents in the finale, with a long summit finish that features a small break in the middle. With ascents of Candriai and Santa Barbara amongst those before the climb to San Valentino, the peloton will already arrive at the base of the final climb very small as the 12.7-kilometer long climb at over 8% that antecedes the final one will already be very difficult and very close to the finish.

Following a descent comes the final climb of 17.4 kilometers at 6.4%, it will max out at 14%. There are two flat sections on this climb that bring the average down, throughout the grand majority of 15 kilometers it averages around 8%. After a rest day some riders may always struggle, but even if not, serious differences can be create here and that includes everyone involved in the GC fight. This will be the first very important summit finish of the race and perhaps the hardest as well.

We do not have the 'mythical' Passo del Mortirolo ascent as we've had in previous years such as 2012, 2015, 2019... This will be an ascent from the south side which is not as steep or difficult but... The Giro designed a stage where the GC can explode fully. Final week of the race and fatigue will be kicking in, and on this day the riders will come right after a brutal mountain stage - with a flat day where they can rest afterwards, which can see the chances of some taking risks increasing.

What we have here is a stage with a rolling start which may see a large breakaway go up the road with many different types of riders. It's not a 'huge mountain stage' but still we have the Passo del Tonale (15 kilometers at 6%) and then of course the Mortirolo itself which will be 12.6 kilometers at 7.5%, it's still hard enough to put in serious attacks. But besides the climb (where the steepest gradients are close to the summit) we will have a very steep and technical descent, and then 33 kilometers of mostly slightly uphill terrain where teammates from the breakaway can be of great use.

It's a day where there can be raids, it's designed for that. The Giro has put a bet on having tough climbs far from the finish this year, to trigger this type of exciting racing and action far from the finish. Here, if there are differences created on the Mortirolo, they can greatly expand later on and having great team tactics and collective strength can decide the race.

Stage 19 is a brute, there will be no way to avoid climbing and there's nowhere to hide. If a rider has a bad day, he will directly lose minutes because there are five categorized climbs from start to finish and three of them are extremely difficult. The stage starts with Croce Serra and ends with a descent in the Valle d'Aosta following another small climb. But inbetween are three long and very difficult mountains, all of similar characteristics. Col Tzecore, Col Saint-Pantaleon and the Col de Joux come back-to-back, all of them 15 and 16 kilometers in length with average gradients of around 7% and with technical descents inbetween. The descents may pose a threat, but naturally the penultimate climb should be the key moment of the day.

This late in the race any mountain stage may have more effect than what it would ordinarily have, but specially with the fatigue built up throughout the day, the Col de Joux specially will be a very hard ascent. It summits with just over 20 kilometers to go and gaps can grow afterwards, there is no doubt that the GC riders will want to go all-out here and the action should kick off early. The climb is 15.1 kilometers at 6.9% and the pink jersey may switch hands if the leader does not have his best legs on the day.

At long last, the Colle delle Finestre. Reportedly, there was a negotiation battle between the Giro d'Italia and Tour de France to have this climb on their route this year, whilst the Vuelta a España will also be racing by very closely. In 2024 we've had the Italian colossus at the Tour de l'Avenir where 18-year old Pablo Torres set a new record up the climb.

This year this will be perhaps the most notable and key climb of the race, coming in the final competitive stage. Stage 20 will largely follow the same route as in 2018, where Chris Froome attacked the climb en route to conquering his first and only Giro. The riders will tackle the ascent that is half tarmac and half gravel. It comes before the ascent to the Sestriere ski station which in itself can see differences but not of the same kind.

This ascent will effectively be a final opportunity to turn the race on it's head, and that's what happened in 2018 as pink jersey Simon Yates collapsed on it's slopes. The climb is 18.6 kilometers long at just over 9%, very steep and very constant without the chance to rest in any spot. The final 7 are on a gravel surface and the climb has a total of 55 hairpins, putting Alpe d'Huez to shame.