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Lon Las Cymru
253 mi / 5-9 days
🇬🇧 8
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Thousands may choose the C2C as their cycling challenge, but the cognoscenti know that it’s Lon Las Cymru that really tests your mettle. This 250-mile route traverses the country’s most mountainous countryside, from the Brecon Beacons to Snowdonia.

And if that sounds spectacular, it is. The scenery is among the finest of any cycle route, starting at Cardiff Bay and crossing valley, hilltop, estuary and strait until it reaches the tip of Wales at Holyhead. This is not a route to rush.

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Getting there


How many days?

Four days is a sensible minimum, but taking six or even seven will give you time to appreciate the sights en route. In particular, make time to see Cardiff if you’ve never been there before. (Holyhead is fairly forgettable, though.)

What sort of bike?

A hybrid or cross bike is well suited, especially one with forgiving gears for climbing. A road bike will need sturdy tyres and to take the occasional diversion; we’d recommend starting at Chepstow rather than Cardiff for such bikes (see below).

Is it suitable for a first-timer?

Only if you’re fit. There’s a lot of climbing for the first-time cycle tourist. That said, if you can manage the C2C, you’ll have a fighting chance here.


Where next?

If you want to extend your tour, then at Bangor, don’t cross onto Anglesey. Instead, turn east and follow NCN 5 along the North Wales Coast – a 70-mile ride to Chester with lovely traffic-free stretches and a colourful array of towns. It’s hilly between Prestatyn and Flint, where the coastal route hasn’t been finished, but otherwise an easy ride.

Are there any route options?

Lon Las Cymru’s main line, aka National Cycle Network route 8, is the route followed by most cyclists: but there’s an alternate start point, and two challenging ‘braids’ in Snowdonia.

Instead of starting in Cardiff, you can set off from Chepstow, just on the English border. Entirely on-road along some lovely quiet lanes, this option (NCN 42) is particularly well-suited to road bikes, avoiding the railway paths and forestry tracks of the main route. It slowly climbs up to the famous Gospel Pass, the highest in Wales, before descending to rejoin the main route near Hay-on-Wye.

In Snowdonia, there’s a tough alternate route between Machynlleth and Porthmadog (NCN 82), crossing the main route at Dolgellau. This throws in some off-roading and some tough climbs, but with genuinely stunning views to match.

Getting there

How do I get there?

There are plentiful trains to Cardiff: Great Western Railway’s expresses from London, regional trains from Birmingham and Bristol, and dozens of local services within South Wales. Booking your bike space is required on the GWR expresses and advisable on the Arriva services down the border from Crewe and Manchester. (Chepstow has fewer trains but you can get there from Gloucester or by changing at Newport.)

Holyhead is the end of the North Wales Coast line. Trains to England are roughly hourly, but they tend to be crammed, so you’ll need to book your bike.

Can I break up the route?

Yes – if you need to tackle the route in several chunks, there are several stations along the way, though nothing from Builth Wells to Machynlleth.

Ride reports & comments

3 days on slick-ish tyres

Being a 'roadie' with 32mm slick-ish (Gatorskin Hardshell) tyres on my Cube Cross Pro (a gravel bike), I adjusted probably a third of my route away from the official NCN…


LEJOG Stage 2

Background: The first leg of our LEJOG ride (which we completed when Covid restrictions, favourable weather and a house move allowed) ended in South Wales, just outside Cardiff. The second…


Riding Lon Las Cymru in 2005

For several years, I’d seen this curious little blue cycle signs with red numbers on them. There was one on the edge of Banbury I’d pass regularly, that pointed to…


Cardiff to Holyhead July 2022

This website contains excellent descriptions, and photographs of the route. I will not add to those but give an explanation of how I planned it, what I took, how…


Virginia to Newtown

From my home in Virginia to Dublin Port and then getting the Ferry to Holyhead. Cycle along the Lon Las Cyrmu to Newtown.


Lon Las Cymru - Machynlleth to Bangor

A Wildlife Trust conference at the Centre for Alternative Technology Centre in Machynlleth gave me the chance to try out some of this iconic route.  I live on the North…


Cardiff to Bangor

The route is described here from Cardiff to Holyhead but is signed in both directions. Opened in 1995, the route runs down the whole length of Wales and is one…



Part of the Lon Las Cymru. Useful for breaking journey to leave 20 miles or so to Holyhead next day before getting the train back.


Canal path overgrown

I cycled along the Montgomery canal from Newtown to Welshpool, July 2022. Path very overgrown. Only a six inch strip in the middle.  Very dangerous. Couldn’t see walkers or any…


Cardiff to Holyhead - 4 days

Fantastic trip, 4 days was c. 6hours/day riding (+lunch,breaks etc).
We got very lucky with the weather - only 20mins rain over 4 days - It's hilly though, so bring…


Ridden this route? Write a ride report and share your experience…

Wed 20 Oct 2021, 14:27

This is an excellent route, highly recommended. Starting in Cardiff, I arrived in Bangor 4 days later.  It's amazing to travel so far on lanes with barely a busy road in between.

The description is pretty accurate, it's a fairly arduous trip with camping gear, especially with the numerous thorns in the lanes as a result of the farmers trimming the hedgerows (October) and the fact that my shifter failed and did half the route in a single gear (hence the reason that I didn't make it to Holyhead in time to make a train connection).  

A huge thanks to Neil at Clive Powell Bikes in Rhayader, who both got me back on the road and recommended a lovely place to take a long lunch (the Lost Arc).

If there is a next time, I might just take bivvy bag and a credit card, it would be fun too, to do the trip with a faster/further approach.  That said, slower would be fun as well.

Mon 6 Jun 2022, 17:18

Here's a very short video of some photos from the trip that tries to show the nature of the lanes on the trip...  Lon Las Cymru video