The walk to the top of Fan y Big takes in some of the most incredible ridge lines in the Brecon Beacons. It’s a steep start, but then you have around 6km of easy ridge line walking, with simply sensational views all the way. Reaching the top is the icing on the cake, and if you luck out with good conditions, it’s a hard spot to leave.
There are a couple of short steep climbs, but the majority of the track is flat. It’s a great option when you don’t want to take on a really hard hike, but don’t want to compromise on views.
Here’s everything you need to know about the Fan y Big circuit walk.
Fan y Big Walk
The stats
Distance: 8.5 miles (14km)
Elevation gain: 465m
Difficulty: Moderate
The Fan y Big circuit walk does have a fair amount of elevation gain, but there is plenty of flat track, and only one steep hill that feels like a slog. Much of the path is in great condition, making for easy walking.
There are however some exceptions, mainly on the main ascent and descent, where the terrain can be very slippery, due to those incredibly small stone ‘steps’ that you find on many of the local walks.
There’s also one long flat section where it’s very rocky underfoot, it’s not slippery, but not relaxing like a smooth path would be.
It’s also worth noting there are other trails which also take in Fan y Big along with the surrounding peaks if you want a more challenging walk.
Starting the trail at Blaen y Glyn Uchaf
The track starts beside the waterfall just outside the car park, and runs to the right of it, heading away from the road.
The beginning of the walk is a baptism of fire as you’ll tackle the steepest part of the whole trail immediately, and it’s a bit of a slog.
This 1km stretch gains 220m in elevation and is the only hard part of the whole walk, but it’s nice to know that when you’ve done it, you have many kilometres of flat ridge walking ahead of you.
As you climb the hill on a series of small uneven stone steps you’ll start to get some pretty great views almost from the off.
After 500m the track noticeably steepens and you’ll be walking on the tiny stone ‘steps’ which are very slippery when wet - more of a problem if you’re descending than ascending.
After this initial steep section the gradient tails off and then the track flattens completely.
Along the ridges
The next 6km are utterly glorious. This was our first walk in the Brecons and it blew me away.
It wasn’t top of my list, so I couldn’t believe how impressive the views were, and how fabulous the ridge lines. It’s steep green mountains as far as the eye can see.
The path is narrow and close to the edge, but it’s very easy walking - as long as you aren’t being buffeted by strong winds (which I can imagine would be a bit hairy).
It was just us and a few hardy sheep up on those ridges and I instantly decided we needed to do a lot more hiking in Wales!
You’ll pass a dry creek crossing after 1km, and it’s worth turning around here, because the views in the other direction are just as magnificent (to be honest you should keep turning all the time because the views are always pretty incredible!).
After a leisurely stroll along the ridge for 2.7km you’ll come to a sharp left turn and start to get a whole new set of views.
This time you can see various towns in the distance, but it’s not long before the vista is wild again.
To the top of Fan y Big
At the turning you’ll head very gently uphill before the trail flattens again. You can see Fan y Big ahead of you, with Cribyn and Pen y Fan further in the distance.
This next part of the walk seemed to be a bit of a wind tunnel, but luckily, when you round the next corner, it dies off again.
The path is slightly rockier than it’s been up to now, but it’s still easy enough.
I couldn’t believe we were still up on the ridges and were having such a leisurely walk - I had been expecting it to be a lot hillier!
Just under 2km from the sharp left turn, you’ll reach a giant cairn, and from here there is a little more flat track before the trail briefly descends.
The steep path is uneven here, with footholds in the dirt, but when dry it’s not slippery.
I can imagine it gets muddy and churned after rain, and that would be much more challenging.
After 250m you turn right to head to the summit of Fan y Big. The next 850m are uphill again, but it’s nothing like that first climb.
It’s relatively gentle, on a mix of grass and rocky track, and it doesn’t take long before you’re standing on the summit.
The top of Fan y Big and the diving board
The top of Fan y Big offers the most spectacular views of some of the Brecons most famous icons: Pen y Fan, Cribyn and Corn Du.
It’s a breathtaking vista in every direction, and we completely lucked out with almost windless conditions, so we could sit up there for over an hour taking it all in.
As well as the views, you’ll also have the chance to step out onto the diving board, one of the most photogenic spots in the area.
It’s not really that exposed, but I wouldn’t venture out in high winds! If you’re really keen to get a good photo, watch out for the afternoon light here.
We were up there around two hours before sunset, and shooting into the sun caused lots of lens flare. We had to wait for the sun to go behind a cloud to get photos. It would have made for a magnificent sunset spot if we’d been there a little later.
Morning light would be a lot nicer than afternoon light, unless it’s a very cloudy day, in which case it doesn’t really matter.
As well as the diving board, there’s plenty of space up on the top where you can spread out and relax. It would make for one truly amazing picnic spot!
The descent
The route down from Fan y Big heads away from the summit, but instead of going back along the same trail you came up on, look for the path heading downhill on the right, very close to the top.
The first couple of hundred metres are not too steep, but then there is a very steep section for 350m. It’s on those little stones again, which can be a touch slippery even in dry weather.
I hate these little stones for descents because I’ve slipped a few times in the past, but this time it was dry and it wasn’t too bad if you take it slowly.
The whole descent is only 650m, so it’s not long before you’re back on flat track again. You’ll come to a large open area and a National Trust sign, we took the path on the left which is wide and stony.
It’s completely flat, but the stones make it less leisurely than it would otherwise be - although we did see someone cycle it, so I guess it’s not that bad!
Completing the circuit
The next 5.5km that finish up the circuit definitely doesn’t have the wow factor you’ve experienced up to now. It’s not that it’s a bad walk, but it’s not as beautiful as walking the ridges.
The views are still pretty and it’s almost entirely flat, so it doesn’t take that long.
The first 2.5km are along the stony path with views out to the peaks in the distance. You’ll then come to a very short (50m) descent on a heavily eroded path.
The trail has loose soil and is very slippery, I found it easier to walk down on the rubbly stones beside it instead.
You then have an equally short ascent before you reach a good gravel path which heads alongside farmland.
Although this is not by any means an exciting part of the walk, we still enjoyed watching the long sheep convoys as we listened to the resident cuckoo in the background.
When we walked in May there was also a lovely sprinkling of wildflowers, including vibrant bluebells.
The gravel path eventually turns into a gravel road, which is forested on both sides so it’s still nice enough, although it does start heading gradually uphill - never the best right at the end of a walk!
After 800m you come out at the main road, and have 500m uphill to go to get back to the car park. It’s not a great end as it’s on the road, but it still has some lovely views.
The best time to do the Fan y Big Walk
The walk up to Fan y Big is very popular, so if you’re hiking on a sunny weekend (especially if that’s during the school holidays), then you’ll want to walk early or late. Not being early birds, we chose to walk late, starting at 5pm.
This worked perfectly for us, as there was barely another soul on the trail (in the school holidays) and we finished around 45 minutes before sunset. Going early would have the same effect and it will ensure you get a spot in the car park, which isn’t overly big.
In terms of weather conditions, it’s ideal to pick a day with low wind, as this walk is very exposed and spends a significant amount of time traversing ridge lines, on the edge of the cliffs.
In winter the track can be covered in snow and ice and would require more preparation.
Getting to the Fan y Big trailhead
The trail begins at the Blaen y Glyn Uchaf car park. There is no time limit or fee for the car park. The Blaen y Glyn Uchaf car park is 40 minutes from Abergavenny, 20 minutes from Merthyr Tydfil and an hour from Cardiff.
The road is sealed almost all the way to the car park and then it becomes a very good gravel road suitable for any vehicle.
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