The Llyn y Fan Fach and Llyn y Fan Fawr circular walk might not have a memorable (or easily pronounced) name, but it’s most definitely one of the most memorable walks in Wales. The views are simply astonishing; with two stunning glacial lakes, miles of epic ridge lines and mountain views that reminded me at times of Iceland and the Alps - although we probably shouldn’t draw comparisons, because this walk is uniquely Welsh.
It’s a relatively challenging trail, as it’s quite long with a fair amount of elevation gain, but the terrain is generally good which makes it feel easier. If you’re feeling adventurous you can even take a dip in the crystal clear waters of Llyn y Fan Fawr, an amazing experience I won’t forget.
Here’s everything you need to know about the walk to Llyn y Fan Fach and Llyn y Fan Fawr.
The Llyn y Fan Fach and Llyn y Fan Fawr Walk
The stats
Distance: 9.2 miles (14.8km) circuit
Elevation gain: 720m
Difficulty: Moderate
If you only want to go as far as Llyn y Fan Fach, the first and most famous of the glacial lakes, the walk is an easy 2.4 miles (1.2 miles each way).
It is uphill on the way, but it’s on a well maintained gravel path with no tricky terrain whatsoever. It’s just a case of keep going up the gradual incline.
If you want to do the full circuit, then it’s more challenging, as it’s significantly longer with plenty of extra hills to climb. You’ll also be walking on more rustic paths and sometimes no path at all. For the most part, the terrain is not challenging when dry, but it’s far from the smooth path up to Llyn y Fan Fach.
The walk is not signposted, but you won’t need a map if you plan on only visiting Llyn y Fan Fach. If you plan on doing the circuit, then you may want an offline map or screenshot our trail notes. The majority of the path is really obvious, but there are a couple of turns you could easily miss if you didn’t know exactly where they were.
The Route
Start / End: Llyn Y Fan Fach Car Park
-> Llyn Y Fan Fach - first glacial lake (+1.2 miles/2km)
-> Bannau Sir Gaer - peak (+1.7miles/2.8km)
-> Fan Brycheiniog - peak (+1.5 miles/2.4km)
-> Llyn Y Fan Fawr - second glacial lake (+half mile/800m)
-> Car Park (+4.25 miles/6.8km)
Starting the trail to Llyn y Fan Fach
The walk begins on an emergency services road, so it’s very well graded and easy to walk on. It doesn’t sound like a glamorous start, but the scenery is really pretty, so it’s not like your average road.
You also obviously don’t need to worry about cars either as it’s strictly for emergency use only, so it’s pleasant enough.
After 850m of gradually climbing on the gravel path you reach a footpath, but it’s just a short hop before you hit the road again.
The gradient steepens a little, but the scenery gets more impressive to compensate.
You’ll pass a small tarn and get some wonderful close up views of the mountains. After you’ve been walking for 1.6km you’ll reach a junction, keep going straight/slightly right to continue towards the lake.
After 300m the trail flattens as it rounds a bend and you’re now just 100m from Llyn y Fan Fach.
Arriving at Llyn y Fan Fach
Llyn y Fan Fach is a very pretty glacial lake, but it’s best viewed from above in my opinion. The water doesn’t quite reach the edges of the lake which makes it less picturesque at eye level.
There was also a slightly funny smell around the water which may not always be there, but definitely detracted a little from the otherwise lovely spot. Having said that it’s still very pretty, surrounded by steep cliffs that add some drama.
Although some people swim at this lake, it is not recommended as there is a chance of catching weil's disease, and there are big danger signs warning you off taking a dip.
It’s not too disappointing though, because the second lake of the track is even more beautiful, quieter and has stunning crystal clear water.
Even if you don’t plan on completing the whole circuit, I’d recommend heading as far up the path on the right of the lake as you have the energy for, because the views are just incredible.
It’s a steep hill and the path is narrow and less manicured, but it’s not particularly difficult. Even heading a short way up will show off Llyn y Fan Fach at its best.
Heading to the mountain tops
The circular walk continues up the narrow path to the right of the lake, and doesn’t stop climbing for the next 1.1km.
It’s steep, but when dry the path is not at all slippery, and you’ll be stopping to turn frequently and admire the view back over the lake.
When you see it from above, nestled between the mountains, it really is a gorgeous scene. The track circles the top of the lake and briefly flattens before you start climbing again, although it’s much more gradual this time.
You now have views out to the peaks ahead of you in the distance, as well as a new angle over Llyn y Fan Fach on the left.
This part of the walk is very exposed to the wind and does at points go quite close to the cliff edge, but you could always move to the right and walk along the grass if winds are high and it feels hairy. The views throughout are breathtaking, both ahead and behind you.
As the track continues you’re still climbing gently higher and higher and the stony dirt path gives way to a grassy track.
For us the conditions underfoot were great, but I did get the feel that after a lot of rain it could get quite muddy.
Approximately 2.8km after leaving the lake, you’ll reach a huge cairn (you’ll already have passed several at this point, but this is the main one marking the route down) and this part of the climb is over.
To the trig point
Once you’ve passed the cairn, you have a short 600m descent. It’s pretty steep, but easy enough in dry conditions.
The path is grassy with some footholds in the dirt, which give you stability as you descend. Unfortunately when this short section is over you’re ascending again!
This time up some stone steps on the next peak along. The scenery in every direction is glorious, with rugged mountains as far as the eye can see.
After another 800m climb, the trail does flatten before undulating all the way to the trig point - albeit with some flat sections for respite.
You’ll pass some interesting red cliffs and get your first glimpse of Llyn y Fan Fawr before passing another cairn and then reaching the trig and wind shelter at the 7.2km mark.
The trail all along this section is in good condition and easy to walk on.
From the trig you can look down over the glacial lake which is spectacular, although it did look somewhat dark and foreboding from above!
Descending to Llyn y Fan Fawr
From the trig you’ll begin descending down to the lake. It’s a great path at first, with large stone steps that are easy to walk on.
As you continue it does turn into those small stone ‘steps’ that can be very slippery - especially when wet.
After 400m you head left and the path gets a little rougher. There are some rocky patches and areas with loose soil, but you can largely avoid what would be slippery dirt sections by using the rocks to get down.
After a couple of hundred metres you’ll be standing at the lake shore. It’s an incredible sight, with crystal clear water backed by mountains. It has a much wilder feel than Llyn y Fan Fach.
If the weather is in your favour it’s a really fantastic place to go wild swimming. It’s shallow at first and you have some small rocks to walk over that are a tiny bit slippery, but it then deepens and you can go for a proper swim.
Naturally the water is freezing, but it’s so clear and invigorating. I swam as the sun set behind the mountains and it quickly became my favourite swimming spot in Wales - so far!
The lake is also a lovely place to stop for a picnic and it’s much quieter than Llyn y Fan Fach, so you feel like you’ve properly escaped into nature.
Completing the circuit
Once you’re at Llyn y Fan Fawr, you’re a little over half way through the walk. The next leg is much quicker than the first half because there is very little climbing to do.
You’ll head along the path that hugs the right side of the lakeshore for just over 1km before the final climb of the track.
This one is only 400m long and gives you some nice views looking back over the lake. You’ll then begin a gorgeous and easy section of flat track that runs along the side of the hill on a good dirt path.
The views of the mountains ahead and the lowlands to your right are just breathtaking, and the good path allows you to relax and really soak it all in for over 1km.
At the 11km mark you’ll see an obvious path on the right that cuts down on to the grass.
This is not the main track, but I’d recommend taking it because it offers unbeatable views of the mountains.
For over a kilometre you’ll be walking on a flat grassy path with the jaw dropping mountains on your left, which offer some really great photo opportunities.
From the turn off to Llyn y Fan Fach it’s just over 1.7km, and it was one of my favourite parts of the whole walk because I couldn’t get enough of those mountain views.
We also had beautiful golden light as it was around an hour or so before sunset at this point.
After the first kilometre along the grassy path, you’ll cross the creek a number of times, but there are stone slabs to use and it’s very easy. You’ll then arrive at the lake 650m later.
From here it’s an easy 2km of descent on the gravel road you came in on.
Overall, this walk is definitely one of our favourites in the Brecon Beacons, with sensational views every step of the way.
The best time to visit Llyn y Fan Fach
Llyn y Fan Fach is a popular place and the good gravel path to reach it means that it’s suitable for anyone who can manage a couple of kilometres uphill.
It can get very crowded, particularly on sunny weekends and in the school holidays - evidenced by the no parking signs miles before the car park!
For this reason, if you’re visiting in peak season, it’s best to hike early or late. If you’re planning on late allow plenty of time as there’s so much to see.
We started at 4.30pm and that worked perfectly, as we finished four hours later, which was still before sunset. Even though it can definitely be done quicker it’s probably worth allowing five hours for the walk so you don’t feel rushed.
We visited in May and the conditions were fantastic. If you are planning on hiking in the winter, I imagine there could be plenty of snow and ice, so you’d need to be much more prepared.
If you can, pick a day where the wind is not too strong. This will make the walk much more enjoyable because the entire trail is exposed and the long section along the mountain tops gets very blustery - even when the wind is slight at lower elevations.
Getting to Llyn y Fan Fach
Llyn y Fan Fach is located in the Brecon Beacons National Park and begins at the Llyn y Fan Fach car park, a 1 hour 15 minute drive from Abergavenny, 1 hour from Merthyr Tydfil and 1 hour 40 from Cardiff.
The last two miles to the car park are incredibly narrow. It is very hard to pass cars here and the popularity of the track means that it can feel quite hairy. This is another good reason to hike early or late, so you at least avoid the worst of the traffic.
The road is sealed all the way and there is plenty of parking, but despite that it gets full quickly. Parking is free and unlimited.
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