Great Welsh Hill Climbs – Llyn Stwlan, Snowdonia

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Initially you’ll be oblivious to the great scenery behind you

Deep within the Snowdonia National Park lies the best kept secret when it comes to Welsh hill climbs: Llyn Stwlan.Epic scenery, steep gradients, hairpins, and an ominous feel (well it is in Blaenau Ffestiniog after all). This one has it all…

Llyn Stwlan is a lake situated 1500 feet above Tanygrisiau, a small village south of Blaenau Ffestiniog. A dam was built in the 1950s to serve the hydro-elecric plant below. A private road owned by the water company snakes up to the foreboding looking dam which can be seen from miles around. The dead-end road is closed to traffic and you need to climb over a gate to access it, but cyclists are tolerated.The climb averages a 10% gradient and ascends 242m (793 feet) over 2.3km.

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Wales’ very own Stelvio Pass

The heart rate increases rapidly as the gradient kicks up straight away and stays at 10% as you climb quickly away from the valley floor. The dam itself is not in sight intially, and you can only see a short distance ahead, which keeps your focus on the legs and not getting demoralised by the climb itself. The rocky terrain and steep hillside you are ascending all adds to the atmosphere.

After about 1.5 km, as the climb begins to bite and your cadence drops, the dam appears, though it still looks far away and high up, and the hairpins emerge. At this point the toughest part is over, so enjoy the steady gradient of the hairpins, designed with lorries in mind so not overly steep. Even with the end destination in sight the hairpins snake left and right, doing a good job of disguising the road ahead, meaning you don’t really know the climb is over until you arrive at the foot of the impressive dam itself.

Photo 02-07-2016, 14 34 00Now for the first time can you can truly enjoy the panoramic views. Breathe deep, enjoy the stunning scenery (reminiscient of Mordor), and get ready for the exhilirating ride back down. The road surface is good but gravelly in places, so remember not to push too hard on the descent (if you value your skin). A cafe is conveniently located at the foot of the climb to allow suitable post-suffering refreshment of your choice.


Summary: Llyn Stwlan may not be the steepest or longest hill climb in Wales, but it makes up for it with the overall quality of the experience. The dramatic mountain scenery of Snowdonia, the relentless gradient, and the added interest of the hairpins at the end, something not often seen in UK climbs, make this climb a real winner. In fact it’s so good that Simon Warren, author of the 100 Greatest Cycling Climbs books, puts it in his Trinity Of Pain, his overall top 3 climbs in the UK, which says it all.

Have you ridden Llyn Stwlan or know of a better climb? If so let me know in the comments below…

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