The 10 Hardest Bike Climbs in Wales

Cycling Wales

Photos clockwise from top left:  Bwlch y Groes (Wales #1, UK #2 hardest);

Stwlan Dam (Wales #1, UK #2 most epic); Entering Wales in Llanymynech;

Cardiff Castle; Welsh flag flying over Cardiff Castle (center)

Wales is a wonderful country with great people, extraordinary scenery and EPIC bike climbs!!  We have had the great fortune of documenting the most epic and hardest climbs in Wales in both 2018 and 2022.  We believe we have located and thoroughly documented the Top 10 Hardest (by Fiets and by Simon Warren) and 10 Most Epic (Simon Warren) and these are accessed via the Map or List above on the Wales Home page just above this Climb Area Summary.

In 2021 we contacted Simon Warren requesting his picks for the Top 10 Most Epic and Top 10 Hardest bike climbs in (1) Wales, (2) England, (3) Scotland, and (4) the UK.  Below is a list of Simon’s choices for Wales Top 10 Hardest and Top 10 Most Epic.  The photos in the collage at the top of this page are of PJAMM’s Top 10 Hardest per the Fiets Index.  While our Fiets list overlaps Simon’s for some climbs, the 2 lists do give you a nice sense of the objective and subjective Top 10 hardest Welsh climbs.

A little bit about Simon Warren - We contacted Simon Warren with our request for his Top 10 lists because we consider him the Gold Standard and cyclist with the most thorough and comprehensive knowledge of hill climbing by bike in the UK.  Simon Warren has published many books on cycling climbing in the UK (e.g. for this page:  100 Greatest Climbs - A Road Cyclist’s Guide To Britain’s Hills; Cycling Climbs of Wales; see also https://www.100climbs.co.uk/books ).  As of 2022, Simon Warren has published 12 cycling climbing books - 10 focusing on the UK, one on TdF and the other on the Giro.  I have purchased and relied heavily on several of these books in deciding what climbs to include on the PJAMM Website for the UK.  We owe a great debt of gratitude to Simon Warren for his books generally and for his contribution of Top 10 lists for PJAMM Cycling.

TOP 3 HARDEST BIKE CLIMBS IN WALES (FIETS INDEX)

#1 HARDEST WELSH CLIMB - BWLCH Y GROES

Cycling Bwlch y Groes, Wales

Ride 1.6 miles gaining 1,206’ at 14.1%

This extraordinary climb is in the northwestern section of Wales in the Snowdonia mountain region. This is the highest paved road and hardest bike climb in Wales.  Bwlch y Groes means “Pass of the Cross.”  

We completed this jewel in August 2018 and because it is so epic,  came back for a second go in June 2022.

#2 HARDEST WELSH CLIMB -THE COWLYD

Cycling The Cowlyd, Wales

Ride two miles gaining 1,329’ at 12.5% average grade. 😓

WOW - enough said!  This climb is simply a monster with several stretches in the red zone - above 16%, including one massive stretch at 20% for 200 yards.  This climb is ranked #3 on PJAMM’s FIETS formula-based difficulty index, as well as the UK Top Hardest Climbs list provided to us by Simon Warren before our second trip to document the UK’s top climbs in 2022 -- thus, it’s The Real Deal!

#3 HARDEST WELSH CLIMB -BWLCH PENBARRA TO JUBILEE TOWER

Cycling Bwlch Penbarras to Jubilee Tower, Wales

Climb summary by PJAMM Cycling’s Brad Butterfield - he climbed this one in 2018 and 2022.

It is really tough to crown just one climb in Wales as a favorite after riding so many over our few weeks of riding in June 2022. That said, Bwlch Penbarra is certainly a top three for US. We parked at the Church in the town of Llanbedr Dyffryn Clwyd (try saying that TWO times fast . . ), and I recommend parking there and not attempting to traverse any part of the actual climb route in a car. In fact, there is a sign at the start warning that the road is ‘Unsuitable for motor vehicles.’  Although I assume this is mostly to keep tourists away as we intersected multiple residents traveling the road in their cars.

TOP 3 HARDEST BIKE CLIMBS IN WALES (SIMON WARREN)

#1 HARDEST WELSH CLIMB -AFON DDU

Cycling the indomitable Afon Ddu, Wales

Ride only 600 meters but at a stunning 21.3% average grade.

This climb has the steepest 500 meter segment in all the UK.

Simon Warren (100 Greatest Cycling Climbs, UK) ranks this as the hardest climb in Wales and he will get no argument from us on that front! This climb comes with the steepest 500 meters in all of the UK at 25%, and it comes at the beginning of the climb so be prepared to strain at the outset.

#2 HARDEST WELSH CLIMB -THE COWLYD

[summarized above]

#3 HARDEST WELSH CLIMB - MELIN Y COED

Cycling Melin y Coed, Wales

Ride two miles gaining 1,055’ at 10.3% average grade.

This climb has one very steep segment near the beginning of the climb: a full half-mile at 16.5%.  Simon Warren lists this as the third hardest climb in Wales, and sixth toughest in all the UK.

#4.  Bwlch y Groes

#5.  Cwm Eigiau

#6.  Rowan YHA

#7.  Llanguicke Road

#8.  Rhiwr Road

#9.  Devil’s Staircase

#10.  Fflord Penllech

TOP 3 MOST EPIC BIKE CLIMBS IN WALES (SIMON WARREN)

#1 MOST EPIC WELSH CLIMB - STWLAN DAM 

Cycling the incomparable Stwlan Dam, Wales

Ride 1.8 miles gaining 916’ at 10% average grade.

Not only is this listed as the #1 most epic bike climb in Wales and #2 in the UK, we consider it a Top 25 Most Epic World Climb - it’s THAT AMAZING!!  This climb is breathtaking and we will return and do this one again - it’s just that unique, inspiring and exceptional.

#2 MOST EPIC WELSH CLIMB - BWLCH Y GROES

[Summarized above under Fiets Top 10 Hardest]

#3 MOST EPIC WELSH CLIMB - THE COWLYD

[Summarized above under Fiets Top 10 Hardest]

#4.  Black Mountain

#5.  Devil’s Elbow

#6.  Electric Mountain

#7.  Llanberis Pass

#8.  Migneint Pass

#9.  Machynlleth Mountain

#10. Gospel Pass