Pramartino - stage 18
Pretty much the only climb on stage 18, the ascent of Pramartino on the way to Pinerolo isn't long, but it is pretty steep.
At just over 4.5km on the stage, the climb ramps up to a maximum of 17 per cent in the middle section, with the rest of it not really getting below 10 per cent.
The general classification will still be on the line by this point, so watch out for some attacks by the big names on the climb as there's only 20km to the finish from the top.
Colle Dell'Agnello - stage 19
The Colle Dell'Agnello marks the Giro's passage into France for a couple of days and they'll have to work hard to get up to the border.
While the Strava segment shows it as a nine kilometre climb, the riders go uphill for around 70km from Saluzzo to the border at the top of the climb.
The toughest gradients come near the top of the Agnello, maxing out at 15 per cent and holding at over nine per cent for much of the nine kilometres, with riders reaching the highest point of the whole race.
And that's just the first climb of the day...
Risoul - stage 19
When the riders get into France it's downhill all the way to the foot of the climb to Risoul, where stage 19 finishes.
It's not the hardest climb in the world but the legs and bodies of the climbers will be cold from the very long descent from the Agnelle.
It maxes out at 10 per cent in the first third of the climb and from then is a steady 8.5 per cent to the top. With the GC still up for grabs it'll likely to be a battle ground all the way up, with attacks likely to come on the preceding descent.
Col de Vars - stage 20
At just six per cent in average gradient, the Col de Vars shouldn't cause any problems, but it's the fact that it comes immediately at the start of stage 20 which makes it hard.
The riders will have to get their warm-ups done before the stage if they're to be in any state to be up at the front of the peloton in the first 20km.
There's not a metre of flat on the entire stage, making it one of the toughest in the whole race, so if there's still anything to play for in the general classification, expect to see some action in these opening exchanges.
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Col de la Bonette - stage 20
Once they've descended from the Col de Vars the peloton hits the even longer and even tougher Col de la Bonette, taking the riders up to over 2,700m.
It'll be a long, cold descent down to Isola at the foot of the third big climb of the day, with almost 40km of downhill, interupted only by a little flat bit after 25km.
With the stage only 134km in length we could see attacks on the pink jersey wearer on the early climbs, just like we did on stage 16 on Tuesday.
Colle della Lombardia - stage 20
As if two 20km ascents weren't enough, the organisers have chucked in a third one near the end to really test the climbers' resolve.
The Col de la Lombarde brings the riders back into Italy for the final assault up to Sant'Anna di Vinado, where the finish line is located.
Like the first two climbs on the stage, the Lombarde isn't particularly steep, it's just relentlessly long, especially after the climbs that have come before.
It's last chance saloon for GC contenders to launch their attacks, with the climb to the finish not really long enough to make up minutes of time.
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Stuart Clarke is a News Associates trained journalist who has worked for the likes of the British Olympic Associate, British Rowing and the England and Wales Cr