The steepest and hardest cycling climbs in the world — fearsome road gradients to put on your bike trip bucket list

Mirror, mirror on the wall, which road is the steepest of them all? While there are lots of horrendously sharp off-road sections, cobbled byways and paths in the world, in this article we’ve selected some of the most infamous cycling climbs one can tackle on a humble road bike, ranging from the savagely short and sharp to the brutally long and arduous, and numerous sadistic stingers that fall somewhere in between.  

Image: Steve Thomas

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With road.cc being based in the UK, two of the choices are from our neck of the woods and the rest are an eclectic mix of classics and lesser-known beasts spanning all the non-Antarctic continents.

We've split our selections up into four categories: short 'n' sharp, long epics, lesser-known slopes, and assorted legendary climbs. You'll need anything from an agonising couple of minutes to a good few hours of hot and sweaty climbing to tick these off, so hopefully there's something for every type of incline enthusiast. 

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While we've included Strava segments for most of these climbs, it's worth noting that Strava data and other stats out there aren't always completely accurate when calculating the average and steepest gradients, or in some cases they just don't exist for lesser-known climbs. With this being our ultimate shortlist, we're also well aware that some very famous climbs are missing (Hardknott-something?) so do let us know any omissions you consider absolutely sacrilegious in the comments below and they might make it into the next update.  

Without further ado... 

Short 'n' sharp

Ffordd Pen Llech (Wales)

Now just the second-steepest street again, ah well (Flickr Creative Commons, licenced under CC BY 2.0)

The extremely steep and twisted 300m slope of Ffordd Pen Llech in Snowdonia, North Wales winds up through the lower western flanks of the picturesque town of Harlech and on towards its historic castle. Should you have chance to look back while grappling with its slopes (it's a one-way street, in a downward direction) you may be treated to some sweet coastal views.

This climb ousted New Zealand's Baldwin Street in 2019 to claim the title of the steepest street in the world, with a brutal 37.45% pitch being found along its way. However, the folks from the land of the long white cloud were not happy with the assessment from those in the land of the eternal cloud, as the measurement was taken on the inside of a hairpin bend, of which Baldwin Street has none. A re-evaluation proclaimed the Welsh slope at 28.6% in comparative mid-road terms, thus Baldwin Street reclaimed its title.

Ffordd Pen Llech Strava segment

Baldwin Street (New Zealand)

As mentioned above, it's not often roads can regain a title when it comes to measurements of steepness, but after sitting pretty and standing tall as the steepest street in the world for a decade, Baldwin Street in Dunedin, New Zealand, was ousted from the hot seat by an old Welsh dragon, only to reclaim its title on a subsequent re-measurement.

As of this moment the 300m vertical and straight-line strip of suburban concrete, which averages an 18% overall grade but hits 35% at its most severe, is ranked as the steepest street in the world by Guinness World Records. It's just 0.37km in length, and of the few brave souls to have cycled up it the fastest time to do so is 1min 19secs, giving you an idea of its brutal steepness. 

Baldwin Street Strava segment

Bamford Clough (England)

(Image: Simon Warren/Twitter)

Rearing its skinny neck like a cobra about to strike, this climb out of the Peak District village of Bamford was recently brought to the attention of the cycling world by Simon Warren, author of the popular 100 Greatest Cycling Climbs series. It's now considered one of the steepest road climbs in the world.

The smooth but narrow Tarmac-covered 'road' gets steep from the off, and it just jacks itself ever-steeper as it runs its course of just 700m to meet New Road above the village.

The average gradient is estimated at 21%, and although official gradient measurements have yet to agree, it is estimated to hit 36.5% towards the summit, which could potentially make it the steepest road in the world. It can be tackled on a road bike, in theory anyway... 

Bamford Clough Strava segment

Long epics

Alto de Letras (Colombia)

Alto de Letras is widely considered the longest road climb in the world at just over 80km. The Mauna Kea climb in Hawaii is longer but has a lot of gravel sections, so this Colombian epic makes our list. 

This climb is so lengthy that those who conquer it will experience both tropical and alpine climates during their huge ride. The road ascends a ridiculous 3,700m from the bottom to the top. Passing the entire Central Cordillera of the Andes, the climb passes the Nevado del Ruiz, the second highest active volcano in the Northern Hemisphere, and still maintains a surprisingly green landscape despite being so high up. 

It's no wonder Colombia produces so many world-class climbing talents. A couple of ascents of the Alto de Letras would put more elevation into the legs than most riders climb in a month. 

Alto de Letras Strava segment

Tulu Dimtu (Ethiopia)

(Rod Waddington, licenced under CC BY-SA 2.0 on Flickr Creative Commons)

Ethiopia has some amazing mountains, and the 41km climb from 2,648m altitude to the 4,377m summit in the Bale Mountains National Park (450km from Addis Ababa) is the highest paved road climb in Africa.

It’s a steady but quite rough road climb to the 4,000m high Sanette Plateau, with the last 4km of the climb being on a dirt road and a little steeper. A gravel bike is recommended for the final part. 

Haleakala (Hawaii, USA)

An amazing road ride up #Haleakala. #Maui #cycling #relentless pic.twitter.com/ewIMZbZjdG

— kootenaybiker (@kootenaybiker) November 6, 2014

The 58.9km-long Haleakala in Maui has 3,032m of climbing, and is one of the longest cycling climbs in the world. Starting out from Pala Maui, the road climbs at an average of 5%, but hits 12% in some short sections, making it a relentless killer of a ride.

There is an annual race up the mountain, which takes place at the end of June. Check out www.cycletothesun.com.

Haleakala Strava segment

WuLing Pass (Taiwan)

(MiNe, CC BY 2.0 on Flickr Creative Commons)

Like the Alto de Letras, this fearsome pass is considered to be over 80km in length all-in (though the Strava segment is 51km), with some spectacularly twisted road climbs within it.  

It starts on the east coast at Hualien and passing through the dramatic Taroko Gorge on its way to the highest road summit in Taiwan (3,275m) and there are some crippling 15% plus gradients towards the end of the ride too, making for a venomous sting in the tail of a very long climb.

Held annually (at the end of October) is the 103km Taiwan KOM Challenge, which is perhaps the best known of all single day uphill events, and it is also often considered the toughest of all, although you can ride it at any time. Just keep an eye on the weather...

Ijen (Indonesia)

The narrow and plentiful road climbs of Indonesia are insanely steep and long, and the 32.4km (in full, there are variations) climb from Banyuwangi at just under 100 metres above sea level up to the Ijen volcanic crater at 1,803m must rank as one of the steepest and toughest climbs in the world.

It ambles along nicely at first, apart from the odd steep sector. This means that the official stats list 6% as the average grade, although the second half of the climb is positively vertical, with pitches hitting 28% briefly. Strava actually shoes the steepest section at 35%, and some estimate 41% grades on some sections. Anyone who has tackled it by bike would probably agree... 

This is a brutal climb that famously forces even the best pro climbers in Asia to their feet when races such as the Tour of East Java and Tour of Ijen visit here.

Ijen Strava segment

Khardung La (India)

This 39km long climb is of often claimed as the world’s highest 'motorable' road (3,519m to 5,358m), and with that claim it had to make the cut. Kardung La is indeed one high-rise beast of a climb.

The traditional ascent side is from Leh, and although it is motorable the road is not sealed, meaning that a low-geared gravel bike is best. There is also a lot of military traffic on the road, thus it’s not the solitary slog you might hope for. Gradients are modest (5% average, 9% steepest), although the ever-thinning air makes it one tough cookie to munch on. The Tagalang La Pass is in the same region, and is the same height, although there is a meter or so of measurement disputed. It's a must to add on if you do find yourself riding here.

Khardung La Strava segment

Lesser-known slopes

Scanuppia (Italy)

45%, anyone? (Image: Richard Peploe)

Italy does seem to have its unfair share of steep surfaced roads, and many of them have carved their evil way into the hallowed archives of the great Italian races. One of the very steepest but lesser known of these climbs is the Scanuppia, which can be found pinned to a steep-sided valley just above the town of Rovereto, not far from the shores of Lake Garda.

The climb is just shy of 9km in length and averages some 13.4% grade, which is cruel enough in its own right, but it does somewhat bely the true demons of this climb – the sectors that top 40% steep in places, and even hit 45% for a few frightful pedal revs. road.cc contributor Richard Peploe and his wife Ruth attempted it on a tandem in 2017, with Richard admitting this was the first time he’d ever had to stop while tackling an ascent on the bike.

Also in 2017, the folks at La Flamme Rouge proclaimed that the Pozza San Glisente in Lombardy was actually the toughest climb in the world, but as it's kind of grassy and not properly surfaced, we're sticking with the Scanuppia for our unsung Italian selection.

Scanuppia Strava segment

Jonaskop (South Africa)

Widely considered one of the hardest road climbs in South Africa, Jonaskop is just shy of 15km in length and averages 8.5%. As you'll see in the video above from the annual Jonaskop challenge - where riders and runners take on the slopes - that 8.5% doesn't tell the full story, and the KOM for its Strava segment is 54:52 by pro cyclist Simon Andreassen. 

Jonaskop Strava segment

Doi Pha Tang, Chiang Rai (Thailand)

(Image: Steve Thomas)

It often surprises people to find that the north of Thailand is very mountainous, with the highest peak topping out at above 2,600 metres. These mountains are very steep-sided and come laced with extremely steep and very hot road climbs, which when combined can make a sunny day on the Ventoux look like a spring ride in the park.

Perched high above the Mekong River on the far north western Thai/Laos border with Laos is Doi Pha Tang, a lofty outpost manned largely by local hill tribe communities. There are a few peaks along this borderline ridge, with the 13km climb from Ban Pang (Wiang Kaen, Chiang Rai) to the village of Pha Tang and then on up the rough and twisted road to the summit above being particularly harsh.

The road goes up in several very long and steep ramps with some respites in between, which makes the steeper sections vaguely more bearable, although they do top 20% in many sectors (according to Komoot). Still, having been up here many times I would estimate that there are a few pitches that are as much as 25-30%, especially on the short old road section before the village.

Doi Pha Tang Strava segment

Legendary climbs

Mont Ventoux (France)

The Ventoux might just be the most famous cycling climb of them all, and is high up on any road cyclist's bucket list who hasn't yet conquered its mean slopes. 

The 'Giant of Provence' rises high above the plains of western Provence, boldly standing tall and alone. This huge pale-faced volcanic cone makes for one of the toughest climbs around because it's relentless, very warm in summer, and very exposed and gusty in the final third. On a hot day the pale grey surface will turn this climb into a fiery furnace.

Just before the summit is a small and humbling memorial to fallen British ace Tom Simpson, who collapsed and died here in the 1967 Tour. Of course, the Ventoux has been the stage for many less tragic happenings at the Tour de France too, such as Eddy Merckx' victory in 1970, Pantani overcoming Lance Armstrong in 2000 or Chris Froome's run in 2016. 

The toughest ride up Ventoux is from Bedoin (21.8-kilometres), with an average gradient of around 7.4% to the 1,912m-high summit. There are few hairpins on this climb, which make it torturous for the mind and legs. It will take most mortals in excess of two hours to complete. 

Mont Ventoux Strava segment

Alto de L'Angliru (Spain)

The Angliru is possibly the most famous and feared climb that features in the Vuelta a España, and yet it's a relative newcomer to the scene.

This beast can be found just south of Oviedo in Asturias, which is in the far north of Spain. From the start point in the village of La Vega to the summit of the Angliru is 14.5 kilometres. The start is at 300 metres above sea level, and the summit at 1,560 metres. The gradient is exceptionally steep from the start of the climb, averaging 10.1% overall but hitting 24% in places.

Probably one of the last places you'd want a vehicle to break down

The only respite is the very short middle section, where it flattens out before getting even steeper. There are harrowing gradient and distance marker posts placed along the road, which can be either a curse or a blessing depending on how you're feeling. 

Alto de L'Angliru Strava segment

Monte Zoncolan (Italy)

The 10.5km climb of the Zoncolan is well-known to cycling fans, although with it being located a tad off-piste in the far east of the Italian Alps, many cyclists visiting Italy often choose to skip it and head to the better-known roads of the Stelvio or Gavia instead.

If you do make this pilgrimage, take the time to ride it in both directions. They're slightly different in flavour and length, but both carry a nasty bite.

The average gradient from the classic Ovaro side is 11.5%, although it does ramp up to 20% for long strides and hits 23.6% at its steepest. This is a climb that most pro racers fear, and many of the non-climbers will rate it as the toughest of all road climbs in pro cycling.

Monte Zoncolan Strava segment

Genting Highlands (Malaysia)

Image: Steve Thomas

Genting Highlands is perhaps the most famous road climb in all of Asia, and with good reason. It's known as 'The Beast of the East' among cyclists, and having grappled at its relentless and torturously steep, hot, and humid slopes a time or three, I can indeed say that this is one of the toughest climbs in pro cycling. Few who have ridden it would argue with that.

There are a couple of measured climb options, with the Genting Sempah 19.8km route being the most ridden, and there is a fair old climb to reach this point from the city too. All approaches do end up on the same evil highway to hell, though. 

Image: Steve Thomas

Luckily (or not) you can no longer officially ride the full climb, as the casino and theme park owners at the summit don’t want any two-wheeled hindrance to traffic plying this road. That said, you can ride halfway up (the easy bit), and some still do find loopholes reach the top.

There are many conflicting stats for the climb, and it’s often graded at between 7-10% overall which is due to a long flatter stretch before the true nastiness. This is where the gradients rarely dip below 14%, hitting 24% regularly, and on the inside lines they do spike much more with claims of 48% made by some. 

Genting Highlands Strava segment

Mount Washington (USA)

(Image: Joe Viger)

Regarded as the most fearsome climb in the USA, the Mount Washington Auto Road is actually closed to bikes outside of organised events. If you do get chance to enter the Mt. Washington Auto Road Bicycle Hillclimb - that has just had its 50th edition - it's definitely one to tick off your bucket list. 

Starting from an altitude of 465m and going up to 1,873m with an average slope of 11.6%, the 12km climb begins at the auto road toll booth, through forests and then breaks through the trees as you head towards the summit. If you manage to finish, you'll end up on the highest peak in the Northeastern USA, and in one of the windiest places on earth. 

Back in 2014, a group from London set themselves the challenge of flying from London to New York City, taking an NYC hire bike to New Hampshire to ride up Mount Washington, then getting back to London inside 36 hours. We've still no idea why, but you can watch the video above to get an idea of how tough this climb is.

Mount Washington Strava segment

Col du Galibier (France)

A brief bit of flat at the foot of the Galibier before things head north

 
This one has to rank as one of the toughest - if not the toughest - and highest of the Alpine climbs. It's arguably harder when tackled from the Col du Telegraph side, which means climbing two big cols without any respite in-between. Topping out at an air-less 2,646m with an average gradient of 6.1% for some 18 kilometres, this is one gruelling climb.

Featuring in the Tour de France many times and first used in 1911 (when all but three riders were forced to walk) the Galibier hosted the Tour's first ever summit finish in 2011 to celebrate 100 years since its first appearance in the race, with Andy Schleck winning on the day. The Strava KOM and QOMs are currently held by Romain Bardet and Erica Magnaldi in times of 46:03 and 1:02:36 respectively.

Col du Galibier Strava segment  

What have we missed? Let us know in the comments.