This year's Giro d'Italia will take the likes of Sir Bradley Wiggins and Vincenzo Nibali over some of the most iconic climbs in cycling.
From the spectacular Passo di Stelvio to the legendary Col du Galibier, the ascents will combine steep gradients with seemingly endless stretches of uphill asphalt to test the riders to their limit.
Here, we highlight the climbs to look out for and the ones that could prove decisive in the race for overall victory.
Col du Mont Cenis, Stage 15
The Col du Mont Cenis is one of three French climbs that the 2013 Giro will visit and while it is far from the steepest of the race, it is the longest at a demoralising 25.5km. The setting of the summit is stunning, with a series of switchbacks on the higher slopes eventually topping out alongside a picturesque Alpine lake. The category-one climb, which will be tackled from the south, comes too early in both the stage and the race to have a decisive say on the general classification, but its sheer length will have a sapping effect on the riders ahead of a hilly final week.
Col du Galibier, Stage 15
Research any list of "Europe's greatest cycle climbs" and the Galibier will almost certainly be on it. However, its fame and notoriety comes not from the Giro, but rather its long-held association with the Tour de France. The Giro's organisers decided to borrow it for the first time for this year's race and also installed it as a summit finish, adding its sobering height and stunning setting to an already dramatic last week. The race will ascend the category-one Galibier from the north, having already scaled the Col du Telegraphe in the run-up. The road dips down slightly after the Telegraphe summit, before rearing back up for an epic, 18.1km climb averaging 6.8 per cent in gradient.
Passo Gavia, Stage 19
The Gavia can sometimes be overshadowed by its near neighbours, the Passo dello Stelvio (see below) and Passo di Mortirolo, but that is not to say this beautiful and challenging pass is any lesser a climb. It is over 17km long and has an average gradient of 7.9 per cent, yet that doesn't tell the whole story, because certain sections kick up violently to as steep at 16 per cent and the switchbacks on its higher slopes are the equal of the Stelvio. The Giro will this year ascend via the southern side, from the town of Ponte di Legno, at the very start of stage 19, before testing the riders with a fast and winding descent into the ski resort of Bormio.
Passo dello Stelvio, Stage 19
The Stelvio is quite simply one of the most iconic roads in the world. The spectacular switchbacks of both its western and eastern flanks are the stuff of cycling and motorbiking legend and on any given day you will find it littered with people working their way slowly up towards the 2,758m summit. For the cyclists, the climb is a humbling experience, with both its punishing length and high altitude each taking their toll. This year's Giro will ascend from Bormio in the south-west - a category-one ascent of 21.7km, averaging 7.1 per cent in gradient - before descending down the Stelvio's famous eastern hairpins to the town of Prato. It arrives mid-stage in 2013, but could still have a key say on the outcome of the race.
Val Martello, Stage 19
Val Martello doesn't carry the fame and notoriety of the Gavia or Stelvio, but at over 22km in length and with two sections late in the climb that reach a stinging 14 per cent in gradient, it is no less an obstacle. The climb also comes after the peloton has tackled the Gavia and Stelvio already the same day, so by the time the race reaches it, legs will be weary energy reserves depleted. The category-one climb also has the potential for a spectacular finish, with a short, flatter section 4km from the line being followed by a steep rise that will provide the perfect platform for late attacks.
Passo Giau, Stage 20
Along with the Stelvio, Gavia and Tre Cime di Lavaredo (see below), the Giau is one of the most feared high-altitude and long-distance climbs in Italy. A winding road ending on a summit situated among the piercing peaks of the Dolomites, it is spectacular and stubborn in equal measure. This year's Giro will tackle it from the southern side and, starting from the town of Caprile, the category-one climb is 15.6km long and averages a leg-sapping eight per cent, with some sections ramping up to over 11 per cent. Its formidable slopes could thin down the peloton ahead of a high-speed descent and subsequent stage finale on Tre Cime di Lavaredo.
Tre Cime di Lavaredo, Stage 20
The summit of Tre Cime di Lavaredo is unquestionably one of cycling's most spectacular settings. Situated high in the Dolomites, the road reaches a summit surrounded by jagged mountain-tops and, in particular, the Three Peaks of Lavaredo, after which the climb is named. The category-one climb from the ski resort of Cortina d'Ampezzo is actually split in two, with the 22km distance including a short section of downhill after the Passo Tre Croci has been summitted. The road then kicks back up for another 7km to the finish line that averages a punishing 8.6 per cent in gradient. Arriving at the end of the penultimate stage of the Giro, Tre Cime di Lavaredo will be where the race will be finally won or lost.